MacOS is one word

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

@@ -6,7 +6,7 @@ weight = 1
 Gutenberg provides pre-built binaries for Mac OS, Linux and Windows on the
 [Github release page](https://github.com/Keats/gutenberg/releases).
 
-## Mac OS
+## MacOS
 
 Gutenberg is not currently available on Homebrew at the moment.