Feature request

Feature description
Allow a delay when activating AFK using the /afk command, which would be cancelled upon being attacked or moving. This would allow the AFK freeze mode to co-exist with user-initiated AFK, while preventing it from being used for instant invulnerability when a player was getting low health, which is kinda cheating.

I recommend the delay to be a new separate config variable, to allow it to be set independently from TP delay. Also because AFK is a distinct thing from TP so it will be less confusing this way.

How the feature is useful
Allows players to be protected while AFK, without waiting the entire AFK timeout period, while also preventing it from being used as an unfair way to avoid dying.