add: Add DevOps section to free programming books list

[jutionck]

Added DevOps section with Docker and Kubernetes resources.

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What does this PR do?

Add resource(s)

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Description

This PR introduces a new DevOps section and adds free learning resources for Docker and Kubernetes, including the open-source repository kubernetes-fundamental, which helps readers learn Kubernetes basics using hands-on examples.

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Why is this valuable?

DevOps skills—especially Docker and Kubernetes—are essential in modern software engineering, yet free curated learning resources in this category are still limited in the list. Adding this section improves topic coverage for backend, DevOps, and cloud-native learners. It also provides beginners with practical, foundational material useful for real-world development and deployment workflows.

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How do we know it's really free?

All added resources are publicly accessible without payment or sign-in requirements. The Kubernetes resource links to an open GitHub repository that is freely available for anyone to read, clone, or download.

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For book lists, is it a book? For course lists, is it a course?

The Kubernetes resource is a learning repository / documentation-style resource, commonly accepted in the repo when the material is structured as educational content. The DevOps section categorizes it appropriately under free programming resources, not under book/course lists.

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Checklist

• [x] Searched for duplicates
• [x] Included author and platform where appropriate
• [x] Added in alphabetical order with correct formatting and spacing
• [x] Used descriptive and informative PR title
• [x] No paywall, no restricted access

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Follow-up

I will monitor GitHub Actions results and resolve any warnings if necessary.

[github-actions[bot]]

Linter failed, fix the error(s):

free-programming-books/books/free-programming-books-id.md
3:1-34:32  warning  Alphabetical ordering: swap l.32 and l.31  alphabetize-lists  remark-lint

[github-actions[bot]]

Linter failed, fix the error(s):

free-programming-books/books/free-programming-books-id.md
  3:1-34:24  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
55:1-56:126  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 62:1-62:97  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint

[github-actions[bot]]

Linter failed, fix the error(s):

free-programming-books/books/free-programming-books-id.md
    3:1-34:24  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   38:1-39:96  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  43:1-44:147  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  48:1-48:130  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  52:1-53:126  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   59:1-59:97  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  63:1-65:136  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   69:1-71:84  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  75:1-80:106  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  84:1-87:122  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  91:1-92:165  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 96:1-101:154  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 105:1-110:73  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
114:1-115:151  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
119:1-119:190  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 123:1-123:83  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
127:1-131:101  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
135:1-135:157  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 139:1-140:71  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
144:1-145:129  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
149:1-152:108  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
156:1-156:194  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
160:1-160:157  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
164:1-164:107  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
168:1-169:128  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
173:1-183:148  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 187:1-192:76  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
196:1-197:119  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
201:1-202:121  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 206:1-215:59  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 219:1-221:82  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint

[github-actions[bot]]

Linter failed, fix the error(s):

free-programming-books/books/free-programming-books-id.md
    3:1-34:24  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   37:1-38:96  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  41:1-42:147  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  45:1-45:130  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  48:1-49:126  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   54:1-54:97  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  57:1-59:136  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   62:1-64:84  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  67:1-72:106  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  75:1-78:122  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  81:1-82:165  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
  85:1-90:154  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
   93:1-98:73  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
101:1-102:151  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
105:1-105:190  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 108:1-108:83  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
111:1-115:101  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
118:1-118:157  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 121:1-122:71  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
125:1-126:129  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
129:1-132:108  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
135:1-135:194  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
138:1-138:157  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
141:1-141:107  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
144:1-145:128  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
148:1-158:148  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 161:1-166:76  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
169:1-170:119  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
173:1-174:121  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 177:1-186:59  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint
 189:1-191:82  warning  Incorrect number of blank lines between last section and next heading  blank-lines-1-0-2  remark-lint

[jutionck]

why linter???

[eshellman]

It's usually not helpful to add a category for a single resource. Try to find another category, or see if there are other books in our lists that would fit into your category. Here you have two levels of categories for a single resource. Devops is OK as a category, just omit the kubernetes subcategory