Callback when a command is executed

[MonzUn]

Is your feature request related to a problem? Please describe.
I would like to log admin commands to Discord for DiscordLink, but there is no way to know when the admin_command log is written to or when the command itself gets invoked.

Describe the solution you'd like
A callback when a command is executed with parameters for who invoked the command, the command level (user, admin etc), the name of the command and the parameters used.

Describe alternatives you've considered
If the log writer could have a callback, that would work well enough.