feat: merge enhanced

[Toricane]

About

This pull request merges most of the features from the enhanced ext.
I am aiming for no breaking changes.
This will be a draft until I am finished merging the features and the documentation.

Things that are added:

1. A Command object, simplifying command decorators
2. Subcommand system in the Command object
3. default_scope key word argument in Client, letting you set a default scope for all commands (except those you disable)
4. @option() decorator that adds options to commands in a single line
5. Utilities such as:
   • @autodefer() decorator that automatically defers the command if delay is exceeded
   • spread_to_rows() helper function that spreads components into a list of ActionRows automatically
6. A new way of creating an ActionRow (pun intended)
7. Command.error decorator allowing a callback coroutine when a command errors

Checklist

• I've ran pre-commit to format and lint the change(s) made.
• I've checked to make sure the change(s) work on 3.8.6 and higher.
• This fixes/solves an Issue.
  • (If existent):
• I've made this pull request for/as: (check all that apply)
  • Documentation
  • Breaking change
  • New feature/enhancement
  • Bugfix

[Toricane]

Wait what I didnt mark it ready for review, how did that happen
how do I make it a draft again
done

[EepyElvyra]

Wait what I didnt mark it ready for review, how did that happen
how do I make it a draft again
done

Could've been me, idk maybe the app did some shit because of my bad network

[Toricane]

Ready for review!

[i0bs]

Move the new design changes to migrations.rst as well as clarification on that page for other features.

[Toricane]

Oh I forgot about that, thanks
Should I keep it in the quickstart and add the migration in migration.rst, or remove it from quickstart.rst and move it to migration.rst?

[i0bs]

Oh I forgot about that, thanks Should I keep it in the quickstart and add the migration in migration.rst, or remove it from quickstart.rst and move it to migration.rst?

Migration details should only be present in migration. However, if you're trying to show alternative methods, that is fine without the need to mention a specific version.

[EepyElvyra]

LGTM I think