Add more time based expiry invite code options

Greetings

I run private discord chat server and it is growing at a code pace.  For security reasons we have the invite code posted in only one place and it is currently set not to expire.  However this isn't practical either from a security stand point.

I would like to see additional time based expiry options beyond 1 day.  7 days, 14 days and 1 month would be good.  Right now expiry based on number of uses isn't practical for my use case.  There are days where we get more than 100 users joining the server.  

Cheers

Brian