Implement Collections feature for grouping related prompts, instructions, and chat modes (#232)

* Initial plan

* Implement core Collections feature with YAML parsing and README generation

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

* Complete Collections feature implementation with validation, tooling, and documentation

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

* Update generated README files to include collections instructions

* Fix YAML parsing logic bug: replace impossible condition with proper indentation check

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

* Refactor: Extract YAML parser to shared module and improve user experience

Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>

* fixing task and file permissions

* Better args handling

* Adding some more collections

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: aaronpowell <434140+aaronpowell@users.noreply.github.com>
Co-authored-by: Aaron Powell <me@aaron-powell.com>

collections/testing-automation.collection.yml

@@ -0,0 +1,36 @@
+id: testing-automation
+name: Testing & Test Automation
+description: Comprehensive collection for writing tests, test automation, and test-driven development including unit tests, integration tests, and end-to-end testing strategies.
+tags: [testing, tdd, automation, unit-tests, integration, playwright, jest, nunit]
+items:
+  # TDD Chat Modes
+  - path: chatmodes/tdd-red.chatmode.md
+    kind: chat-mode
+  - path: chatmodes/tdd-green.chatmode.md
+    kind: chat-mode
+  - path: chatmodes/tdd-refactor.chatmode.md
+    kind: chat-mode
+  - path: chatmodes/playwright-tester.chatmode.md
+    kind: chat-mode
+
+  # Testing Instructions
+  - path: instructions/playwright-typescript.instructions.md
+    kind: instruction
+  - path: instructions/playwright-python.instructions.md
+    kind: instruction
+
+  # Testing Prompts
+  - path: prompts/playwright-explore-website.prompt.md
+    kind: prompt
+  - path: prompts/playwright-generate-test.prompt.md
+    kind: prompt
+  - path: prompts/csharp-nunit.prompt.md
+    kind: prompt
+  - path: prompts/java-junit.prompt.md
+    kind: prompt
+  - path: prompts/ai-prompt-engineering-safety-review.prompt.md
+    kind: prompt
+
+display:
+  ordering: alpha
+  show_badge: true