ci: fix and cleanup ci workflows

.github/workflows/changelog-generator.yaml

@@ -2,7 +2,7 @@ name: changelog-generator
 
 on:
   push:
-    branches: [ develop ]
+    branches: [ develop, stable ]
 
 jobs:
   generate_changelog:

.github/workflows/npm-publish.yml → .github/workflows/publish-release.yml

@@ -1,22 +1,43 @@
 # This workflow will publish a package to GitHub Packages when a release is created
 # For more information see: https://help.github.com/actions/language-and-framework-guides/publishing-nodejs-packages
 
-name: Publish to NPM
+name: Publish Release
 
 on:
   release:
     types: [created]
 
 jobs:
+
   publish-npm:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@master
+        with:
+          ref: 'develop'
+
       - uses: actions/setup-node@v2
         with:
           node-version: 12
           registry-url: https://registry.npmjs.org/
+
       - run: npm install
+
       - run: npm publish
         env:
           NODE_AUTH_TOKEN: ${{secrets.NPM_TOKEN}}
+
+  merge-branch:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+        with:
+          ref: 'develop'
+
+      - name: Merge develop -> stable
+        uses: devmasx/[email protected]
+        with:
+          type: now
+          from_branch: develop
+          target_branch: stable
+          github_token: ${{ github.token }}