Group Factory

[PenguinBoi12]

This PR adds a factory to create a group that can be used to extend the bot outside of the scope of the bot object. This is a first step to handle bigger bot.

# math_group.py
from matrix import group


@group("math", description="Math operations")
async def math_group(ctx):
    await ctx.reply("Math help")


@math_group.command()
async def add(ctx, a: int, b: int):
    await ctx.reply(f"{a + b}")

...

# bot.py
from matrix import Bot
from my_bot.math_group import math_group

bot = Bot(...)

...

bot.register_group(math_group)

[PenguinBoi12]

This is a small fix that prevents errors from calling send_help twice.

[chrisdedman]

LGTM