Is your feature request related to a problem? Please describe.
no

Describe the solution you'd like
to add a custom player count message which shows up when a player hovers over the player count

Describe alternatives you've considered
none

Additional context
a mod which implements this in spigot: https://www.spigotmc.org/resources/cbmfc-%E2%98%85-custom-serverlist-playerlist-private-message-friend-party-maintenance-system-%E2%98%85.55905/
an example screenshot:

I want this too @jpenilla