[FEATURE] Create a Help Command

[OmegaRC59]

Essentially create a "help" command that will spit out a description of any registered command. Rather than suggesting we do special commands, just have "help" as a standard.

Additional idea: If help is entered with no arguments, print a list of every command, but with no description of those commands.

So essentially, if you type "help rmode" it'll tell you things like "rmode 1: wireframe mode", etc.