Add build workflow

.github/workflows/page.yml

@@ -0,0 +1,31 @@
+name: Build
+
+on: [push]
+
+jobs:
+  ruby:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby: [ '2.7.4', '3.3' ]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+      - name: Install github-pages gem
+        run: |
+          gem install github-pages
+      - name: Install
+        run: bundle install
+      - name: Build jekyll site
+        run: bundle exec jekyll build
+      - name: Build the site in the container
+        run: |
+          docker run \
+          -v ${{ github.workspace }}:/srv/jekyll \
+          -v ${{ github.workspace }}/_site:/srv/jekyll/_site \
+          jekyll/builder:latest \
+          /bin/bash -c "chmod -R 777 /srv/jekyll && jekyll build --future"