Add build GHA

.github/workflows/main.yml

@@ -0,0 +1,71 @@
+name: S3/CloudFront deployment beta.swcarpentry.carpentries.org
+
+on:
+  push:
+    branches: main
+  schedule:
+    - cron: '30 */6 * * *'
+  workflow_dispatch:
+
+jobs:
+  build-website:
+    if: github.repository_owner == 'carpentries'
+    runs-on: ubuntu-22.04
+
+    defaults:
+      run:
+        shell: bash
+
+    concurrency:
+      group: ${{ github.workflow }}-${{ github.ref }}
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true  # Fetch Hugo themes (true OR recursive)
+          fetch-depth: 0    # Fetch all history for .GitInfo and .Lastmod
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Setup Hugo
+        uses: peaceiris/actions-hugo@v3
+        with:
+          hugo-version: 'latest'
+          extended: true
+
+      - name: Install NPM deps
+        run: |
+          npm install @alpinejs/intersect
+
+      - name: Update Theme
+        run: |
+          hugo mod get -u github.com/carpentries/carpentries-hugo-theme
+          hugo mod npm pack
+          
+      - name: Build
+        run: hugo --minify
+
+      - name: List Built Files
+        run: ls "$GITHUB_WORKSPACE/public/"
+
+      - name: Deploy to AWS S3
+        id: deploy
+        uses: fmichonneau/s3-sync-action@log-output
+        with:
+          args: --acl public-read --follow-symlinks --delete
+        env:
+          AWS_S3_BUCKET: ${{ secrets.AWS_S3_BUCKET }}
+          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
+          SOURCE_DIR: public/
+
+      - name: Invalidate CloudFront
+        uses: chetan/invalidate-cloudfront-action@master
+        env:
+          PATHS: /*
+          AWS_REGION: 'us-east-1'
+          DISTRIBUTION: ${{ secrets.DISTRIBUTION }}
+          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}