BANE grid option help string

[tjgalvin]

Maybe it was just me but I got a little confused by the help string for the --grid option in BANE. My first reading made it seem like it was specified in units of the synthesised beam. Reading the code though it is clear that it is expected in units of pixels, and of left unset something is derived using the restoring beam encoded in the fits header.

It might be good to add an explicit in units of pixels in the help string. it only became clear to me when i went reading through the code.

It would be nice to have an optional flag asking BANE to treat these user provided numbers in units of the restoring beam instead of pixels. I think most of the infrastructure to support this is already in place.

[PaulHancock]

Good point. I've updated the text.