Add github actions

- docs: checks that readme has been generated correctly
- tests: linting and tests

.github/workflows/docs.yml

@@ -0,0 +1,20 @@
+name: Docs
+on:
+  push:
+    branches: master
+  pull_request:
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Set up Git repository
+      uses: actions/checkout@main
+
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: '2.7'
+        bundler-cache: true
+
+    - name: Outdated readme check
+      run: bundle exec readme:outdated

.github/workflows/tests.yml

@@ -0,0 +1,27 @@
+name: CI
+on:
+  push:
+    branches: master
+  pull_request:
+jobs:
+  tests:
+    strategy:
+      matrix:
+        platform: ["ubuntu-latest", "macos-latest"]
+        ruby: [2.7, 3.0, 3.1, 3.2]
+    runs-on: ${{ matrix.platform }}
+    steps:
+    - name: Set up Git repository
+      uses: actions/checkout@main
+
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        bundler-cache: true
+
+    - name: Run linter
+      run: bundle exec rake lint
+
+    - name: Run tests
+      run: bundle exec rake test