Setup the base documentation.
Added content to the index.
Adding more documentation.
Restructuring documentation

Removed the old structure of the documenation and broke it down a
different way. Finished writing up the section on the builtin help
command.
Tidy up of code.

Added a couple of full stops for messages that are printed out to the user
and removed a debug statement from the usage class which printed a message
out to the user when creating command documentation.
Completed the documentation on commands.

The documentation for commands covers the creation of commands and the
following argument types that it accepts:

* Positional/required.
* Optional.
* Flags.

It also goes into the following "special" commands:

* The None command.
* The help command.
Completed the inheritance page.

Updated the documentation for using inheritance to have an example which
used the example script else where in the documentation and ported it to
use the inheritance model.