add build for npm

Author: andrejpk

.github/workflows/publish-github.yml

@@ -28,6 +28,7 @@ jobs:
           node-version: 12
           registry-url: https://registry.npmjs.org/
       - run: yarn
+      - run: yarn build
       - run: yarn publish
         env:
           NODE_AUTH_TOKEN: ${{secrets.npm_token}}