Add gh workflow.

Author: tschaefer

.github/workflows/ruby.yml

@@ -0,0 +1,25 @@
+---
+name: Ruby
+
+on:
+  push:
+    branches: ["main"]
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby-version: ['3.3']
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+      - name: Run tests
+        run: bundle exec rake rspec

.yamllint

@@ -0,0 +1,10 @@
+---
+extends: default
+rules:
+  indentation:
+    indent-sequences: consistent
+  truthy:
+    allowed-values: ['true', 'false', 'yes', 'no', 'on', 'off', '1', '0']
+    check-keys: true
+
+# vim:ft=yaml