Update CI for Zola setup

Author: senekor

.github/workflows/main.yml

@@ -31,7 +31,9 @@ jobs:
       - run: rustup override set ${{ env.RUST_VERSION }}
       - uses: Swatinem/rust-cache@9d47c6ad4b02e050fd481d890b2ea34778fd09d6 # v2.7.8
 
-      - run: cargo run
+      - name: Install Zola
+        run: cargo install --locked --git https://github.com/senekor/zola --rev 620bf3c46a39b41db30b1e91756a995bbff84d3a
+      - run: zola build
       - run: cp CNAME ./public/
       - run: touch public/.nojekyll