ci: 🎡 add linting github action

.github/workflows/lint_pr.yml

@@ -0,0 +1,22 @@
+name: Lint PR Changed Files
+on: 
+  # by adding a schedule task to this workflow we will automatically
+  # begin serializing read-only runs and handling them. The cron job
+  # below is set to run every 15 minutes, GitHub will ignore anything
+  # under 10 minutes and run every 10 minutes anyway.
+  schedule:
+    - cron: '*/30 * * * *'
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - closed
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: bradennapier/eslint-plus-action@v3.4.0
+      with: 
+        reportIgnoredFiles: true
+        reportWarningsAsErrors: true

.github/workflows/pull_request_ci.yml

@@ -14,7 +14,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v2
       with:
         node-version: ${{ matrix.node-version }}
     - name: npm install, build, and test