add release notes job to release workflow (#399)

Author: abhinayagarwal

.github/workflows/release.yml

@@ -80,3 +80,12 @@ jobs:
           git push https://gluon-bot:[email protected]/$GITHUB_REPOSITORY HEAD:master
         env:
           PAT: ${{ secrets.GITHUB_TOKEN }}
+
+  release-notes:
+    runs-on: ubuntu-latest
+    needs: [build]
+    steps:
+      - name: Create GitHub release
+        uses: softprops/action-gh-release@v2
+        with:
+          generate_release_notes: true