Updated Deferred Rendering (markdown)
Described normal encoding.
Formatting.
Expanded geometry-buffer section.
Added chrominance sub-sampling alternative geometry buffer.
Explained reasoning for using deferred shading rather than deferred lighting.
Add 'Implementation' section, and sub-sectioned 'Geometry Buffer' to it.
Added 'Using Deferred Rendering' section.
Added 'Geometry Buffer' section.