Add flow to run HTML Proofer on PRs

Author: Pablo Vieira

.github/workflows/pr-check.yml

@@ -0,0 +1,22 @@
+name: Pull Request Check
+
+on: [pull_request, workflow_dispatch]
+
+env:
+  NOKOGIRI_USE_SYSTEM_LIBRARIES: 'true'
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: 2.7.4
+        bundler-cache: true
+    - run: gem install bundler -v '< 2.5'
+    - run: bundle install --jobs=3 --retry=3
+    - run: bundle update
+    - run: bundle exec jekyll build
+    - run: time bundle exec rake test