Add simple doc code test

.github/workflows/test-doc-code.yaml

@@ -0,0 +1,57 @@
+name: Run Unit Tests
+
+on:
+  # trigger on pull requests
+  pull_request:
+
+  # trigger on all commits to main
+  push:
+    branches:
+      - 'main'
+
+  # trigger on request
+  workflow_dispatch:
+concurrency:
+  group: "${{ github.workflow }}-${{ github.ref }}"
+  cancel-in-progress: true
+jobs:
+  test:
+    name: test (${{ matrix.os }}, ${{ matrix.python }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: true
+      matrix:
+        os: [ubuntu-latest]
+        python: ['3.10', '3.11', '3.12', '3.13']
+        include:
+          # Other tests
+          - os: 'macos-latest'
+            python: '3.10'
+          - os: 'macos-latest'
+            python: '3.13'
+    steps:
+    - name: Checkout
+      uses: actions/checkout@a5ac7e51b41094c92402da3b24376905380afc29  # v4.2.1
+    - name: Set up Python ${{ matrix.python }}
+      uses: actions/setup-python@f677139bbe7f9c59b41e40162b753c062f5d49a3 # v5.2.0
+      with:
+        python-version: ${{ matrix.python }}
+    - name: Set up Python environment
+      uses: glotzerlab/workflows/setup-uv@3573ddaebf3290e00bfb150b82a46412192a61d3
+      with:
+        # only-binary: ":none:"
+        lockfile: ".github/requirements${{ matrix.python }}.txt"
+    - name: Install package
+      run: |
+        python --version
+        uv pip install . --no-build-isolation --no-deps --system -v
+    - name: Extract Documentation Code
+      run: |
+        awk > '
+              /```python/ {in_block=1; file="README_code_block_" ++count ".py"; next}
+              /```/ {in_block=0; next}
+              in_block {print > file}
+              '
+              README.md
+    - name: Test Documentation Code
+      run: for f in README_code*.py; do python3 "$f"; done && echo OK