remove newsletter, switch to npm

Author: HugoDF

.github/workflows/nodejs.yml

@@ -9,7 +9,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x]
+        node-version: [lts/*]
 
     steps:
     - uses: actions/checkout@v1
@@ -19,8 +19,8 @@ jobs:
         node-version: ${{ matrix.node-version }}
     - name: yarn install, format, and build
       run: |
-        yarn
-        yarn format
-        yarn build
+        npm i
+        npm run format
+        npm run build
       env:
         CI: true