Remove local documentation files from repository

- Remove CLAUDE.md, CLAUDE_CSCORE.md, and cloudscribe-syndication-docs.html from git tracking
- Add these files to .gitignore to prevent future commits
- Files remain available locally but are excluded from version control

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: claude

.gitignore

@@ -199,3 +199,8 @@ src/demo.Web/appsettings.local.overrides.json
 tools/**
 !tools/packages.config
 
+
+# Local documentation files
+CLAUDE.md
+CLAUDE_CSCORE.md
+cloudscribe-syndication-docs.html