add: workflow to assert changelog updates

.github/scripts/check-changelog.sh

@@ -0,0 +1,16 @@
+#!/bin/bash
+
+set -e
+
+CHANGELOG_FILE="changelog.md"
+
+git fetch
+
+# Check if the changelog file was modified in the PR
+if git diff --name-only origin/$GITHUB_BASE_REF..$GITHUB_HEAD_REF | grep -q $CHANGELOG_FILE; then
+  echo "Thank you for updating the changelog!"
+  exit 0
+else
+  echo "Changelog has not been updated. Please update $CHANGELOG_FILE!"
+  exit 1
+fi

.github/workflows/changelog.yml

@@ -0,0 +1,24 @@
+name: changelog
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+    branches:
+      - master
+
+jobs:
+  check-changelog:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0 # Need entire git history
+
+      - name: Set up environment
+        run: |
+          echo "GITHUB_HEAD_REF=${{ github.head_ref }}" >> $GITHUB_ENV
+          echo "GITHUB_BASE_REF=${{ github.base_ref }}" >> $GITHUB_ENV
+
+      - name: Check if changelog is updated
+        run: .github/scripts/check-changelog.sh