chore(ci): use Actions to generate changelog

`release-please` will bump the package version and generate changelogs
based on conventionalcommit. It does so by opening a PR every time a
commit lands, and it updates that PR for each subsequent commit.
Publishing to npm is still done manually.

Ref: nodejs#446

.github/workflows/release-please.yml

@@ -0,0 +1,15 @@
+on:
+  push:
+    branches:
+      - master
+
+name: release-please
+jobs:
+  release-please:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: GoogleCloudPlatform/release-please-action@v1.6.3
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}
+          release-type: node
+          package-name: node-core-utils