Azd validate

[spboyer]

This pull request adds a new GitHub Actions workflow to validate Azure Developer CLI templates. The workflow includes steps for setting up the environment, running validation, and creating a detailed GitHub issue if validation fails.

New GitHub Actions Workflow for Template Validation:

• Workflow Setup: Introduced a new workflow file, .github/workflows/validate-azd-template.yml, to validate Azure Developer CLI templates on push, pull_request, and workflow_dispatch events.
• Validation Steps:
  • Installs the necessary dependencies, including Node.js and the Azure Developer CLI.
  • Handles case sensitivity for README.md by creating a symlink if only a lowercase version exists.
  • Runs the mcp-azd-template validation command, captures the output, and determines success or failure based on the exit code.
• Error Handling:
  • On validation failure, creates a detailed GitHub issue with critical issues, warnings, and the full validation output included in a well-formatted Markdown structure.