Add test stage to docs

Add new file with docs tets

Run only in pulls

.github/workflows/docs-test.yml

@@ -0,0 +1,27 @@
+name: Test documentation build
+
+on: [pull_request]
+
+concurrency:
+  group: ${{ github.workflow }}-$${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      - name: Install python
+        uses: actions/setup-python@v4
+        with:
+          python-version: 3.x
+      - name: Setup cache
+        uses: actions/cache@v2
+        with:
+          key: ${{ github.ref }}
+          path: .cache
+      - name: Setup dependencies
+        run: pip install -r docs/requirements.txt
+      - name: Build docs
+        run: mkdocs build --strict