Add release action

Author: liZe

.github/workflows/release.yml

@@ -0,0 +1,42 @@
+name: Release new version
+on:
+  push:
+    tags:
+      - v*
+
+jobs:
+  pypi-publish:
+    name: Upload release to PyPI
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/tinycss2
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+      - name: Install requirements
+        run: python -m pip install flit
+      - name: Build packages
+        run: flit build
+      - name: Publish package distributions to PyPI
+        uses: pypa/gh-action-pypi-publish@release/v1
+  add-version:
+    name: Add version to GitHub
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Install requirements
+        run: sudo apt-get install pandoc
+      - name: Generate content
+        run: |
+          pandoc docs/changelog.rst -f rst -t gfm | csplit - /##/ "{1}" -f .part
+          sed -r "s/^([A-Z].*)\:\$/## \1/" .part01 | sed -r "s/^ *//" | sed -rz "s/([^\n])\n([^\n^-])/\1 \2/g" | tail -n +5 > .body
+      - name: Create Release
+        uses: softprops/action-gh-release@v2
+        with:
+          body_path: .body