Suggestion: Change 'radius' to 'halfwidth' in Neighbourhood-methods

[dodohjk]

I am reading the wiki for Neighbourhood methods
https://github.com/metno/gridpp/wiki/Neighbourhood-methods

The function calculates the statistics for a square around a gridpoint. Radius is defined as the half width of the square.
I suggest changing this to halfwidth or similar.
This would make it clearer that it is not considering a circular radius.