New "Azd best practices" skill (#2549)

* Add Azure Developer CLI skill and related documentation

* Add Azure Developer CLI skill to README with usage instructions and bundled assets

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

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Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

skills/azure-developer-cli/examples/azure.yaml

@@ -0,0 +1,33 @@
+# yaml-language-server: $schema=https://raw.githubusercontent.com/Azure/azure-dev/main/schemas/v1.0/azure.yaml.json
+name: sample-app
+
+infra:
+  provider: bicep
+  path: ./infra
+  module: main
+
+services:
+  api:
+    project: ./src/api
+    language: ts
+    host: appservice
+  web:
+    project: ./src/web
+    dist: dist
+    language: ts
+    host: staticwebapp
+
+# Add hooks only when the default lifecycle cannot express the requirement.
+# Keep nontrivial commands in scripts/azd and provide both OS variants.
+hooks:
+  preprovision:
+    windows:
+      shell: pwsh
+      run: ./scripts/azd/validate.ps1
+      interactive: false
+      continueOnError: false
+    posix:
+      shell: sh
+      run: ./scripts/azd/validate.sh
+      interactive: false
+      continueOnError: false