Created a GitHub Actions CI workflow. Temp rename CircleCI version

Author: ckenst

.circleci/config.yml .circleci/temp-rename-config.yml.circleci/config.yml renamed to .circleci/temp-rename-config.yml

@@ -0,0 +1,30 @@
+name: Build and Test
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: 3.1
+          bundler: 2.4.17
+
+      - name: Install dependencies
+        run: |
+          gem install bundler
+          bundle install
+
+      - name: Build Jekyll site
+        run: bundle exec jekyll build --verbose
+
+      - name: Run htmlproofer
+        run: bundle exec htmlproofer ./_site --check-html --disable-external