maint: Add ci workflow to check links

.github/workflows/check-links.yml

@@ -0,0 +1,52 @@
+name: check-links
+on:
+  push:
+    branches: [ main ]
+    paths:
+      - '**/*.md'
+      - '**/*.rst'
+      - '.github/workflows/check-links.yml'
+      - '.github/workflows/check_links_config.json'
+  pull_request:
+    paths:
+      - '**/*.md'
+      - '**/*.rst'
+      - '.github/workflows/check-links.yml'
+      - '.github/workflows/check_links_config.json'
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  check-links:
+    runs-on: ubuntu-latest
+    if: ${{ github.actor != 'dependabot[bot]' && github.actor != 'otelbot[bot]' }}
+    timeout-minutes: 15
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v6
+
+      - name: Get changed markdown files
+        id: changed-files
+        uses: tj-actions/changed-files@v46
+        with:
+          files: |
+            **/*.md
+            **/*.rst
+
+      - name: Install markdown-link-check
+        if: steps.changed-files.outputs.any_changed == 'true'
+        run: npm install -g markdown-link-check@v3.12.2
+
+      - name: Run markdown-link-check
+        if: steps.changed-files.outputs.any_changed == 'true'
+        run: |
+          markdown-link-check \
+            --verbose \
+            --config .github/workflows/check_links_config.json \
+            ${{ steps.changed-files.outputs.all_changed_files }} \
+            || { echo "Check that anchor links are lowercase"; exit 1; }

.github/workflows/check_links_config.json

@@ -0,0 +1,14 @@
+{
+  "ignorePatterns": [
+    {
+      "pattern": "http(s)?://\\d+\\.\\d+\\.\\d+\\.\\d+"
+    },
+    {
+      "pattern": "http(s)?://localhost"
+    },
+    {
+      "pattern": "http(s)?://example.com"
+    }
+  ],
+  "aliveStatusCodes": [429, 200]
+}