docs: Updated the AVM post deployment guide based on latest changes

[Prajwal-Microsoft]

Purpose

• ...
  This pull request significantly improves the clarity and usability of the AVMPostDeploymentGuide.md by restructuring the document, expanding prerequisite details, and providing step-by-step instructions for post-deployment tasks. The changes make it easier for users to follow the setup and verification process after deploying the Conversation Knowledge Mining solution accelerator.

Documentation Structure & Clarity Improvements:

• Added an Overview section and reorganized the guide into clear, numbered steps for post-deployment, making instructions easier to follow.
• Expanded the Prerequisites section with detailed requirements for Azure permissions, tool versions, and links to setup guides.

Step-by-Step Guidance:

• Provided explicit instructions for cloning the repository, logging into Azure, and running the data processing script, including tips and warnings for users.
• Enhanced the verification process with a checklist table to confirm successful data upload, AI Search index creation, and application availability.

Additional Resources & Troubleshooting:

• Added links to sample questions and a dedicated troubleshooting section to support users in getting started and resolving potential issues.

Does this introduce a breaking change?

• Yes
• No

Golden Path Validation

• I have tested the primary workflows (the "golden path") to ensure they function correctly without errors.

Deployment Validation

• I have validated the deployment process successfully and all services are running as expected with this change.

What to Check

Verify that the following are valid

• ...

Other Information