docs: link check only on .md files (#2501)

Previously, the link checker ran on all changed files; it has now been
restricted to changed .md files only.

---------

Co-authored-by: Twisha Bansal <58483338+twishabansal@users.noreply.github.com>

Author: rahulpinto19

…hub/workflows/link_checker_workflow.yaml .github/workflows/link_checker.yaml.github/workflows/link_checker_workflow.yaml renamed to .github/workflows/link_checker.yaml .github/workflows/link_checker_workflow.yaml renamed to .github/workflows/link_checker.yaml

@@ -34,7 +34,7 @@ jobs:
         shell: bash
         run: |
           git fetch origin main
-          CHANGED_FILES=$(git diff --name-only --diff-filter=ACMRT origin/main...HEAD)
+          CHANGED_FILES=$(git diff --name-only --diff-filter=ACMRT origin/main...HEAD -- '*.md')
 
           if [ -z "$CHANGED_FILES" ]; then
             echo "No markdown files changed. Skipping checks."