Add comments job

.github/workflows/comments.yml

@@ -0,0 +1,34 @@
+name: RBS Comments
+
+on:
+  push:
+    branches:
+      - master
+  pull_request: {}
+
+jobs:
+  test:
+    runs-on: "ubuntu-latest"
+    container:
+      image: rubylang/ruby:3.1-focal
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install dependencies
+      run: |
+        apt-get update
+        apt-get install -y libdb-dev
+    - name: Update rubygems & bundler
+      run: |
+        ruby -v
+        gem update --system
+    - name: bundle config set with
+      run: |
+        echo "NO_MINITEST=true" >> $GITHUB_ENV
+        bundle config set --local without 'minitest'
+      if: "contains(matrix.container_tag, 'master-nightly')"
+    - name: bin/setup
+      run: |
+        bin/setup
+    - name: Run test
+      run: |
+        bundle exec rake annotate confirm_annotation