ci: add publish workflow

.github/workflows/publish.yml

@@ -0,0 +1,27 @@
+name: Publish Python distribution to PyPI
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set up Python 3.9
+        uses: actions/setup-python@v1
+        with:
+          python-version: 3.9
+
+      - name: Install pypa/build
+        run: python -m pip install build --user
+
+      - name: Build a binary wheel and a source tarball
+        run: python -m build --sdist --wheel --outdir dist/
+
+      - name: Publish distribution to PyPI
+        uses: pypa/gh-action-pypi-publish@master
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}