Update link for "OAuth - The Big Picture"

[thiskevinwang]

What does this PR do?

Update link for "OAuth - The Big Picture"

For resources

Description

Why is this valuable (or not)?

How do we know it's really free?

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

Checklist:

• [ ] Read our contributing guidelines.
• [ ] Search for duplicates.
• [ ] Include author(s) and platform where appropriate.
• [ ] Put lists in alphabetical order, correct spacing.
• [ ] Add needed indications (PDF, access notes, under construction).
• [ ] Used an informative name for this pull request.

Follow-up

• Check the status of GitHub Actions and resolve any reported warnings!

[github-actions[bot]]

Linter failed, fix the error(s):

free-programming-books/books/free-programming-books-subjects.md
896:3-896:134  warning  Missing PDF indication  books-links  remark-lint

[github-actions[bot]]

This Pull Request has been automatically marked as stale because it has not had recent activity during last 60 days :sleeping:

It will be closed in 30 days if no further activity occurs. To unstale this PR, draft it, remove stale label, comment with a detailed explanation or push more commits.

There can be many reasons why some specific PR has no activity. The most probable cause is lack of time, not lack of interest.

Thank you for your patience :heart: