Reminder commands

[mdcfe]

Is your feature request related to a problem? Please describe.
I often forget about things relevant to a conversation and like to set reminders about them, but setting reminders elsewhere can make it harder to remember the context for the reminder.

Describe the solution you'd like
A remindme <time> [message] command that can either ping the sender in a public channel or send a DM after the given time has passed, optionally also including a message.

Additional context
This could possibly separated into a reminder command for public channels that people with Manage Channel can use, and a remindme command that only works in PMs/forbids pinging other people.

This could also be extended by accepting a previous message ID, so when the reminder is sent, it includes a link to the original message making it easier to find the context again. The message ID could also be read from replies instead (eg if I reply to Chew with %^remindme 2h blah, then the reminder could link back to Chew's message).

[Chew]

Command name

%^remindme

Arguments

<time> - Required
[message] - Message

Flags

--dm - To be dm'd instead of invocation

Aliases

%^remind, %^reminder

[Chew]

Could also be expanded to %^remind on a reply to a given message, and be reminded of that message