Update 'README.md'

README.md

@@ -1,3 +1,9 @@
 # gollum
 
-Git-powered wiki with a sweet API and local frontend.
+Git-powered wiki with a sweet API and local frontend.
+
+## Usage
+
+```
+docker run --rm -p 4567:4567 -v $(pwd):/wiki gollumwiki/gollum:v5.3.0
+```