Add description to commands

[Sweattypalms]

Is your feature request related to a problem?

It's hard to find commands and what they do.

Describe the solution / feature you'd like.

/help command that lists all commands (that the user can execute, with the hopefully soon to-be-implemented permission system)

echo - Repeats what the user says

Alternatives you've considered.

NA

Additional Context

Like how bukkit does it, or was it paper? one of those.

#282

I have confimed that...

• ... such a feature does not exist already.
• ... I ticked all the boxes without reading them
• ... such a feature request has not been submitted already.