specify files to run link checker on

Author: erinecon

.github/workflows/docs.yaml

@@ -8,4 +8,6 @@ on:
 jobs:
   docs-checks:
     uses: canonical/operator-workflows/.github/workflows/docs.yaml@main
-    secrets: inherit
+    secrets: inherit
+  with:
+    linkcheck-files: "'*.md' 'docs/**/*.md' 'terraform/**/*.md' './**/*.rst'"