Document handleheight parameter of Legend constructor

Author: dpoznik

lib/matplotlib/legend.py

@@ -262,6 +262,9 @@ def _update_bbox_to_anchor(self, loc_in_canvas):
 handlelength : float, default: :rc:`legend.handlelength`
     The length of the legend handles, in font-size units.
 
+handleheight : float, default: :rc:`legend.handleheight`
+    The height of the legend handles, in font-size units.
+
 handletextpad : float, default: :rc:`legend.handletextpad`
     The pad between the legend handle and text, in font-size units.