Configurable Min Chat Delay

Just as the title says, change `50` to a configurable value [here](https://github.com/kaboomserver/extras/blob/24af535c60ba5a369d77d46eb89cd62dac11cd9a/src/main/java/pw/kaboom/extras/modules/player/PlayerChat.java#L34-L36).

I would implement this myself and create a PR but [I am unable to access papermc.io](https://dinhero21.dev/message/papermc.io-unreachable/), thus can't develop any plugins.
