Document label and milestone actions

README.md

@@ -7,10 +7,77 @@ _This project is currently in its alpha stage and might be incomplete or change
 ## Installation
 
 ```sh
-git clone https://github.com/scientific-python/changelist.git
 pip install changelist
 ```
 
+## Set up your repository
+
+All PRs must have one of the following labels:
+
+- `type: Highlights`
+- `type: New features`
+- `type: Enhancements`
+- `type: Performance`
+- `type: Bug fix"`
+- `type: API`
+- `type: Maintenance`
+- `type: Documentation`
+- `type: Infrastructure`
+
+### Label checking
+
+To ensure that each PR has one of the above labels attached to it,
+we recommend adding the following to `.github/workflows/label-check.yaml`:
+
+```
+name: Labels
+
+on:
+  pull_request:
+    types:
+      - opened
+      - labeled
+      - unlabeled
+
+env:
+  LABELS: ${{ join( github.event.pull_request.labels.*.name, ' ' ) }}
+
+jobs:
+  check-type-label:
+    name: ensure type label
+    runs-on: ubuntu-latest
+    steps:
+      - if: "contains( env.LABELS, 'type: ' ) == false"
+        run: exit 1
+```
+
+### Milestones
+
+We also recommend adding `.github/workflows/milestone-merged-prs.yaml`:
+
+```
+name: Milestone
+
+on:
+  pull_request_target:
+    types:
+      - closed
+    branches:
+      - "main"
+
+jobs:
+  milestone_pr:
+    name: attach to PR
+    runs-on: ubuntu-latest
+    steps:
+      - uses: scientific-python/attach-next-milestone-action@f94a5235518d4d34911c41e19d780b8e79d42238
+        with:
+          token: ${{ secrets.MILESTONE_LABELER_TOKEN }}
+          force: true
+```
+
+See https://github.com/scientific-python/attach-next-milestone-action for more information.
+
 ## Usage
 
 ```sh