Explain in the documentation what time units are valid for mutes

[zambam5]

There is no clear explanation on what units or timeframes are allowed

>>mute @[username] 7d will return [username] muted for 1w but >>mute @[username] 1w does not work.

[jagrosh]

Valid units of time are seconds, minutes, hours, and days. These can be combined in any order, and the input validation for these is quite flexible; all of the following are valid input for time:

2hr30min
4 minutes and 10 seconds
2d 1 minute
6sec and 2 days

I will update the wiki with this in some manner (either in the full command reference or as a referenced page) soon