Only run markdown-link-check when markdown files are included

Author: jeffhandley

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

@@ -3,8 +3,10 @@ name: Check Markdown links
 on:
   push:
     branches: [ "main" ]
+    paths: "**.md"
   pull_request:
     branches: [ "main" ]
+    paths: "**.md"
 
 permissions:
   contents: read