Added npm-publish workflow.

This will auto-publish package to npm & Github packages.

.github/workflows/npm-publish.yml

@@ -0,0 +1,47 @@
+# This workflow will run tests using node and then 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: Node.js Package
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+      - run: npm ci
+      - run: npm test
+
+  publish-npm:
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 14
+          registry-url: https://registry.npmjs.org/
+      - run: npm ci
+      - run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{secrets.npm_token}}
+
+  publish-gpr:
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12
+          registry-url: https://npm.pkg.github.com/
+      - run: npm ci
+      - run: npm publish
+        env:
+          NODE_AUTH_TOKEN: ${{secrets.GH_TOKEN}}