Packaging (#503)

* Publish to PyPI using Github Action
* Reformat CHANGES.md to always add at the top and use consistent language.

Co-authored-by: Hans-Martin von Gaudecker <[email protected]>

.github/workflows/publish-to-pypi.yaml

@@ -0,0 +1,35 @@
+---
+name: PyPI
+
+on: push
+
+jobs:
+  build-n-publish:
+    name: Build and publish Python 🐍 distributions 📦 to PyPI
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11'
+
+      - 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 }}

.gitignore

@@ -38,9 +38,7 @@ waf3-*
 *latexmk
 *synctex.gz
 .*
-!.environment.osx.yml
-!.environment.windows.yml
-!.environment.linux.yml
+!.github
 !.pre-commit-config.yaml
 !.envrc
 .*pdfsvn