Add CI for Rubocop linter

.github/workflows/rubyonrails.yml

@@ -0,0 +1,18 @@
+name: "Ruby on Rails CI"
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+      - name: Install Ruby and gems
+        uses: ruby/setup-ruby@55283cc23133118229fd3f97f9336ee23a179fcf # v1.146.0
+        with:
+          bundler-cache: true
+      - name: Lint Ruby files
+        run: bin/rubocop --parallel

Gemfile.lock

@@ -205,6 +205,8 @@ GEM
       racc (~> 1.4)
     nokogiri (1.15.4-x86_64-darwin)
       racc (~> 1.4)
+    nokogiri (1.15.4-x86_64-linux)
+      racc (~> 1.4)
     oauth (1.1.0)
       oauth-tty (~> 1.0, >= 1.0.1)
       snaky_hash (~> 2.0)
@@ -349,6 +351,8 @@ GEM
       railties (>= 6.0.0)
     tailwindcss-rails (2.0.31-x86_64-darwin)
       railties (>= 6.0.0)
+    tailwindcss-rails (2.0.31-x86_64-linux)
+      railties (>= 6.0.0)
     temple (0.10.3)
     thor (1.2.2)
     tilt (2.3.0)
@@ -386,6 +390,7 @@ GEM
 PLATFORMS
   arm64-darwin-21
   x86_64-darwin-22
+  x86_64-linux
 
 DEPENDENCIES
   action_policy