Set fetch-depth to 0

.github/workflows/validate_markdown.yml

@@ -18,6 +18,8 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4.1.0
+        with:
+          fetch-depth: '0' # Fetch all history for all tags and branches
 
       # https://github.com/marketplace/actions/markdownlint-cli2-action
       - name: Identify changed files
@@ -42,6 +44,8 @@ jobs:
     steps:
       - name: Check out code
         uses: actions/checkout@v4.1.0
+        with:
+          fetch-depth: '0' # Fetch all history for all tags and branches
 
       # https://github.com/gaurav-nelson/github-action-markdown-link-check
       - name: Markdown links