Add markup link checker to GitHub workflow

Author: AArnott

.github/workflows/build.yml

@@ -69,3 +69,13 @@ jobs:
       timeout-minutes: 3
       continue-on-error: true
       if: env.codecov_token != ''
+
+  docs:
+    name: 📃 Docs
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: 🔗 Markup Link Checker (mlc)
+      uses: becheran/mlc@v0.19.0
+      with:
+        args: --do-not-warn-for-redirect-to https://learn.microsoft.com*,https://dev.azure.com/*,https://app.codecov.io/* -p docfx