Include config file in workflow paths trigger

Changes to .github/markdown-link-check-config.json now trigger
the workflow since config changes affect link checking behavior.

Author: ihabadham

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

@@ -6,10 +6,12 @@ on:
     paths:
       - '**.md'
       - '.github/workflows/check-markdown-links.yml'
+      - '.github/markdown-link-check-config.json'
   pull_request:
     paths:
       - '**.md'
       - '.github/workflows/check-markdown-links.yml'
+      - '.github/markdown-link-check-config.json'
   schedule:
     # Run weekly on Monday at 8am UTC
     - cron: '0 8 * * 1'