Link Check: Only check md files

Author: AB-xdev

.github/workflows/broken-links.yml

@@ -20,6 +20,7 @@ jobs:
         id: lychee
         uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2
         with:
+          args: "--verbose --no-progress './**/*.md'"
           fail: false # Don't fail on broken links, create an issue instead
 
       - name: Find already existing issue