Update readme to warn sysops about adult ship names on scoreboard

Update readme.txt to warn sysops about echickens' ship naming convention on the interBBS scoreboard. Seemed easier than trying to setup a self-hosted scoreboard or requiring 18+ on program execution.

approved this merge request

Fucking ships amirite?

mentioned in commit c2959cc0

merged

FWIW if you want to clean up the scoreboard, all you need to do is beat my high scores. Have at it!