Multiple centre points for the shrinking worldborder in an arena

### Suggestion

It'd be great to have the feature that it shrinks onto a number of fixed points in key location on the maps, that we set. If it's a bigger map, then we could set a number of centre points and it'd change the game up each time it's played. 

5 would be ideal if a number has to be set. 

### Additional Information

_No response_