[Request] - Mute/Unmute an user for a period of time

[mirkobrombin]

Is your feature request related to a problem? Please describe.
At the moment, users can only permanent muted.

Describe the solution you'd like
Pass period as command argument:

/mute 1h

using:

• h for hours
• m for minutes
• mm for months
• y for years

Maybe there are better standards to use.

Describe alternatives you've considered
n/a

Additional context
n/a