Add markdown linter workflow (#363)

Author: mcbarton

.github/workflows/markdown-linter.yml

@@ -0,0 +1,39 @@
+---
+name: Markdown-Linter
+
+on: 
+  pull_request:
+    branches: [main]
+    paths:
+      - '**.md'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    name: Linter
+    runs-on: ubuntu-22.04
+
+    permissions:
+      contents: read
+      packages: read
+      # To report GitHub Actions status checks
+      statuses: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          # super-linter needs the full git history to get the
+          # list of files that changed across commits
+          fetch-depth: 0
+
+      - name: Super-linter
+        uses: super-linter/[email protected] 
+        env:
+          VALIDATE_ALL_CODEBASE: false
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          VALIDATE_MARKDOWN: true
+          DEFAULT_BRANCH: ${{ github.base_ref }}