Add GitHub workflows.

.github/workflows/build.yml

@@ -0,0 +1,51 @@
+name: Build and publish
+on:
+  push:
+    branches: [master, dev]
+  # release:
+  #   types: [published]
+
+matrix:
+  version: ["3.9", "3.10", "3.11", "3.12"]
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        os:
+          - windows-latest
+          - macos-latest
+          - ubuntu-latest
+        version:
+          - "3.9"
+          - "3.10"
+          - "3.11"
+          - "3.12"
+
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v4
+      - name: Install Poetry
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install poetry
+      - name: Setup Python
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ os.version }}
+          cache: "poetry"
+      - name: Install dependencies
+        run: |
+          poetry install
+      - name: Build
+        run: |
+          poetry install
+      # - name: Check
+      #   run: poetry run python -c "import cshogi"
+      # - name: Publish
+      #   if: github.event_name == 'release' && github.event.action == 'published'
+      #   env:
+      #     TWINE_USERNAME: ${{ secrets.PYPI_USERNAME }}
+      #     TWINE_PASSWORD: ${{ secrets.PYPI_PASSWORD }}
+      #   run: twine upload dist/*