Remove Guide Docgen (guide Command's Parsers)

[gazmull]

There's a plan to use future utility package akairo-botdoc (to be written). Guide Docgen's source code will serve as the base source code.

Benefits

• Less codebase noises

[gazmull]

Not possible right now, since it involves a lot of hard-coded parsing which is not a great idea. I'll put this on backlog since I'm still planning to create a separate docgen.

[gazmull]

Actually, I've decided to settle with the current codebase of Guide command. It will only need refactors for automated registry of commands. This will be suspended indefinitely.