add release action

.github/workflows/release.yml

@@ -0,0 +1,28 @@
+name: release
+
+on:
+  workflow_dispatch:
+    inputs:
+      release_type:
+        description: "`alpha`, `alpha-minor`, `alpha-major` release?"
+        required: true
+        default: "alpha"
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    if: ${{ github.repository == 'pedroslopez/whatsapp-web.js' }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Bump version and publish to NPM
+        id: publish
+        run: ./tools/publish ${{ github.event.inputs.release_type }}
+        env:
+          NPM_TOKEN: ${{ secrets.RELEASE_NPM_TOKEN }}
+      - name: Create GitHub Release
+        id: create_release
+        uses: ncipollo/release-action@v1
+        with:
+          prerelease: ${{ steps.publish.outputs.PRERELEASE }}
+          generateReleaseNotes: true
+          tag: v${{ steps.publish.outputs.NEW_VERSION }}