ci(markdownlint): add Markdown linting (reanahub#838)

Co-authored-by: Tibor Šimko <[email protected]>

.github/workflows/ci.yml

@@ -193,3 +193,17 @@ jobs:
         run: |
           pip install yamllint
           ./run-tests.sh --check-yamllint
+
+  lint-markdownlint:
+    runs-on: ubuntu-24.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+
+      - name: Lint Markdown files
+        run: |
+          npm install markdownlint-cli2 --global
+          ./run-tests.sh --check-markdownlint

.markdownlint.yaml

@@ -0,0 +1,5 @@
+# Allow arbitrary line length
+MD013: false
+
+# Allow prompt dollar sign in console examples without showing output
+MD014: false