Add info to manual on set grid

A portable, multi-platform, command-line driven graphing utility

Brought to you by: broeker, cgaylord, lhecking, sfeam

Milestone: None

Status: closed-accepted

Owner: nobody

Labels: None

Priority: 5

Updated: 2022-09-07

Created: 2019-03-17

Private: No

If in cartesian mode, and if polar grid is asked to be displayed, we have to set raxis too.
https://sourceforge.net/p/gnuplot/gnuplot-main/ci/master/tree/src/graphics.c#l231
That info should be added to the p. 133 of the manual.

BTW raxis can be unset when in polar mode, and we can still get the polar grid (without the raxis) there.