Run markdown link check only on master or when docs change

Optimize CI by skipping markdown link checks on PRs that don't
modify documentation files. Master branch runs always ensure
comprehensive link validation.

- Remove paths filter from push to master (run on all pushes)
- Keep paths filter on pull_request (only run when .md files change)
- Maintains weekly scheduled runs and manual workflow dispatch

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

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

Author: justin808

.github/workflows/check-markdown-links.yml

@@ -3,10 +3,6 @@ name: Check Markdown Links
 on:
   push:
     branches: [master]
-    paths:
-      - '**.md'
-      - '.github/workflows/check-markdown-links.yml'
-      - '.github/markdown-link-check-config.json'
   pull_request:
     paths:
       - '**.md'