add github action for npm publish

Author: Jayant Krishnamurthy

Diff for: .github/workflows/npm-publish.yml

@@ -0,0 +1,18 @@
+name: Node.js Package
+on:
+  release:
+    types: [created]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      # Setup .npmrc file to publish to npm
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '12.x'
+          registry-url: 'https://registry.npmjs.org'
+      - run: npm install
+      - run: npm publish --access public
+        env:
+          NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}