feat: basic help message

[LordOfPolls]

Re-open of #5 due to unresolvable branch conflict issues.

This is a basic implementation of a help command to tick off one of your points in #3.

Pre-merge utilisation of this is fairly simple

class bot(Snake):
    def __init__(sefl, ...):
        help = HelpCommand(self, show_params=True, ...)
        help.register()

To modify it, pre-merge, i really think just overriding is the way to go. Post merge i would like to introduce some sort of client method to modify help.

This pr is dependant on dev-latest of dis-snake. Specifically NAFTeam/NAFF@af64022

[AstreaTSS]

Right, fair enough, might as well comment on a few things from the old PR while I'm at it:

• For the imports, the point is for there to be less work to be done to change things around. Really, the only things that'll need changing are the molter-specific imports.
• MolterCommand.usage was indeed added in the dev branch... though there was MolterCommand.signature in main.
• Fair enough on the language thing.
• attrs may have a cost during initialization, but that only matters when you're importing the library. When you're running it, it has zero cost. Plus, it makes sense here - who cares about the performance of a help command out of all things? I care about the other stuff attrs allows more.
• The overrides used to completely replace dis-snek's message commands, but now they don't. Even then, there was always the option of not using the overrides and simply not having aliases or subcommand support, so...

As for the pre/post-merge world, yeah, I would like that too. But overall, this looks good! I'll probably briefly test it on my own once I can (might not be for a while) and then merge it in.

[AstreaTSS]

Sorry for taking so long, life got in the way haha.

Anyways, just two (really one) things to review over that I found while doing basic tests.