Add PyPI publish workflow

.github/workflows/pypi.yml

@@ -0,0 +1,28 @@
+name: Publish Python Distributions
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  publish:
+    name: Build and publish to PyPI
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout full source
+        uses: actions/checkout@master
+      - name: Set up python 3.7
+        uses: actions/setup-python@v3
+        with:
+          python-version: '3.7'
+      - 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
+        if: startsWith(github.ref, 'refs/tags')
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_API_TOKEN }}