Setup github actions for standardrb

.github/workflows/ci.yml

@@ -0,0 +1,21 @@
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - '*'
+  push:
+    branches:
+      - main
+
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+      - name: StandardRb check
+        run: bundle exec standardrb