docs: Updated README, azure.yml for minimum azd version 1.18.0

[Vamshi-Microsoft]

Purpose

This pull request updates the documentation and configuration to require Azure Developer CLI (azd) version 1.18.0 or higher for deploying the solution accelerator. It clarifies this version requirement in multiple documentation files and enforces it in the project configuration. Additionally, there are minor formatting improvements.

Azure Developer CLI (azd) version requirement:

• Added a requiredVersions section to azure.yaml to enforce that azd version 1.18.0 or higher is required for deployment.
• Updated docs/LOCAL_DEPLOYMENT.md and docs/NON_DEVCONTAINER_SETUP.md to clearly state and highlight the azd version requirement, including download links and version notes. [1] [2] [3]

Documentation formatting:

• Fixed minor formatting issues in README.md related to deployment instructions.

Does this introduce a breaking change?

• Yes
• No

How to Test

• Get the code

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