docs: Readme updates26367

[Kingshuk-Microsoft]

Purpose

This pull request updates the docs/DeploymentGuide.md file to improve clarity and completeness of deployment instructions, particularly around environment selection, security practices, and post-deployment workflows. The documentation now better distinguishes between sandbox and Well-Architected Framework (WAF)-aligned deployments, adds detailed security guidance for Cosmos DB, and introduces safer redeployment steps.

Deployment environment selection and security:

• Added a dedicated section explaining the difference between sandbox and WAF-aligned deployment options, including step-by-step instructions for enabling required Azure features for production deployments.

• Introduced a comprehensive security considerations section for Cosmos DB, detailing access controls, network restrictions, and RBAC practices for both sandbox and production environments.

Post-deployment workflow improvements:

• Added a "Confirm Your Deployment Environment" section with guidance and visual aids to verify whether resources are deployed in sandbox or WAF-aligned mode.
• Reorganized post-deployment steps into a clear, numbered list, including new instructions for safely redeploying or updating environments without overwriting configuration. [1] [2] [3]
• Included visual references and emphasized the importance of not re-running azd init after initial setup to prevent configuration loss.

Does this introduce a breaking change?

• [ ] Yes
• [x] No

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code check the changes in dev-v3

What to Check

Verify that the readme is up to date