Update brew docs

docs/content/documentation/getting-started/installation.md

@@ -6,6 +6,14 @@ weight = 1
 Zola provides pre-built binaries for MacOS, Linux and Windows on the
 [GitHub release page](https://github.com/getzola/zola/releases).
 
+### macOS
+
+Zola is available on [Brew](https://brew.sh):
+
+```bash
+$ brew install zola
+```
+
 ## Linux
 
 ### Arch Linux