Fixed the height parameter of the "Floating & rotated axis" in Figure 2.9

[furutaka]

The height parameter in Figure 2.9 (coordinates/transforms‐floating‐axis.py) as well as the corresponding line of the code in rst/coordinates.rst, were fixed; they should be the differences in Y (ymax-ymin) instead of (ymax-xmin).

[rougier]

Thanks!