MNT: Auto publish to PyPI

Add long_description_content_type

.github/workflows/publish.yml

@@ -0,0 +1,37 @@
+name: Release
+
+on:
+  push:
+
+jobs:
+  build-n-publish:
+    name: Build and publish Python 🐍 distributions 📦 to PyPI
+    runs-on: ubuntu-latest
+    if: github.repository == 'astropy/astrowidgets'
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.8
+
+    - name: Install python-build and twine
+      run: python -m pip install build "twine>=3.3"
+
+    - name: Build package
+      run: python -m build --sdist --wheel .
+
+    - name: List result
+      run: ls -l dist
+
+    - name: Check dist
+      run: python -m twine check --strict dist/*
+
+    - name: Publish distribution 📦 to PyPI
+      if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags')
+      uses: pypa/gh-action-pypi-publish@master
+      with:
+        user: __token__
+        password: ${{ secrets.PYPI_TOKEN }}

setup.cfg

@@ -17,6 +17,7 @@ exclude = setup_package.py,conftest.py,__init__.py
 name = astrowidgets
 description = Widgets for the Jupyter notebook and JupyterLab
 long_description = file: README.rst
+long_description_content_type = text/x-rst
 author = Astropy Developers
 author_email = mattwcraig@gmail.com
 license = BSD 3-Clause