Add action to check if changelog was updated

.github/workflows/changelog_updated.yml

@@ -0,0 +1,11 @@
+name: Changelog Updated
+
+on:
+  pull_request:
+
+- name: Checkout
+  uses: actions/checkout@v3
+  with:
+     fetch-depth: 2
+- name: Check if CHANGELOG.md was changed
+  run: ! git diff --name-only --exit-code HEAD^1 HEAD CHANGELOG.md