docs: adds docstrings for some properties of InvokableSlashCommand and SubCommand and document Option's attributes

[Snipy7374]

Summary

Adds docstrings for the following properties:

.description (added to InvokableSlashCommand and SubCommand)
.options (added to InvokableSlashCommand)

additionally i feel like we should document some attributes of the Option class, the reference fo SubCommand.description (which is Option.description) is already failing 'cause we're documenting only methods for the Option class

also why the API representation is called and documented as option in this class? https://docs.disnake.dev/en/stable/ext/commands/api/app_commands.html#disnake.ext.commands.SubCommand.option
shouldn't it be called body (which already exists) like other slash command classes?

Checklist

• If code changes were made, then they have been tested
  • I have updated the documentation to reflect the changes
  • I have formatted the code properly by running pdm lint
  • I have type-checked the code by running pdm pyright
• This PR fixes an issue
• This PR adds something new (e.g. new method or parameters)
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)

[shiftinv]

additionally i feel like we should document some attributes of the Option class

Yup, otherwise CI will continue to fail. Option already has a list of parameters which mostly matches the list of attributes, so that section could be rewritten for this purpose.
In that case we should also consider turning this from Option() into Option to show the parameters in the signature.

shouldn't it be called body (which already exists) like other slash command classes?

it's aliased to that, I honestly don't remember if there was a reason for it - @EQUENOS might know

[EQUENOS]

shouldn't it be called body (which already exists) like other slash command classes?

it's aliased to that, I honestly don't remember if there was a reason for it - @EQUENOS might know

It's called option because internally subcommands and groups are actually options with a special type, that's how discord API designed them. We added a body property for convenience, as it's useful in several places.

[shiftinv]

some minor nits - overall, this looks good to me

[shiftinv]

lgtm!