DOC: add draw_idle reference to pyplot.draw

Author: hukaidong

lib/matplotlib/pyplot.py

@@ -968,6 +968,11 @@ def draw():
 
     This is equivalent to calling ``fig.canvas.draw_idle()``, where ``fig`` is
     the current figure.
+
+    See Also
+    --------
+    .FigureCanvasBase.draw_idle
+    .FigureCanvasBase.draw
     """
     gcf().canvas.draw_idle()