The 2.2.6 version was strictly html not Sphinx and Python.
You just had to edit and change html files.
SEE: CodeIgniter 2.2.5 User Guide
Table of Contents / General Topics / Writing Documentation
There you can get the css and the template for creating the documentation.
What did you Try? What did you Get? What did you Expect?
Joined CodeIgniter Community 2009. ( Skype: insitfx )