add CI job to enforce CHANGELOG.md updates

.github/workflows/ci.yml

@@ -4,9 +4,18 @@ name: Go
 on:
   push:
     branches: main
-  pull_request: # don't include branches so that all PRs run.
+  pull_request:
+    types: [opened, synchronize, reopened, ready_for_review, labeled, unlabeled]
 
 jobs:
+  # Enforces the update of a changelog file on every pull request
+  changelog:
+    runs-on: ubuntu-latest
+    skipLabels:
+      - skip-changelog
+      - ignore-release
+    steps:
+      - uses: dangoslen/changelog-enforcer@v3
   build:
     runs-on: ubuntu-latest
     steps: