I believe the OP is using Docco.js (which has been ported to many languages, e.g. Rocco for Ruby, Shocco for Shell, Pycco for Python, Gocco for Go, etc.)
There's different ways to configure the output and layout...the Docco homepage uses a single-column format, whereas the OP uses the double-column format.
http://jashkenas.github.io/docco/
There's different ways to configure the output and layout...the Docco homepage uses a single-column format, whereas the OP uses the double-column format.