Update pygmt/src/grdimage.py

Co-authored-by: Wei Ji <23487320+weiji14@users.noreply.github.com>

Author: Meghan Jones

pygmt/src/grdimage.py

@@ -133,9 +133,9 @@ def grdimage(self, grid, **kwargs):
         intensity, and ambient arguments for that module, or just give
         **+d** to select the default arguments
         [Default is **+a**\ -45\ **+nt**\ 1\ **+m**\ 0]. If you want a more
-        specific intensity scenario then run ``grdgradient`` separately first. If
-        we should derive intensities from another file than grid, specify the
-        file with suitable modifiers [Default is no illumination].
+        specific intensity scenario then run ``grdgradient`` separately first.
+        If we should derive intensities from another file than grid, specify
+        the file with suitable modifiers [Default is no illumination].
     {J}
     monochrome : bool
         Force conversion to monochrome image using the (television) YIQ