test: add github action

builds test site with latest Hugo version

.github/workflows/build-test-site.yaml

@@ -0,0 +1,26 @@
+name: build test site
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - 'wowchemy/**'
+
+jobs:
+  deploy:
+    runs-on: ubuntu-18.04
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: true  # Fetch Hugo themes (true OR recursive)
+          fetch-depth: 0    # Fetch all history for .GitInfo and .Lastmod
+
+      - name: Setup Hugo
+        uses: peaceiris/actions-hugo@v2
+        with:
+          hugo-version: 'latest'
+          extended: true
+
+      - name: Build
+        run: hugo --minify