Update colorbar.py

Clarified documentation of "shirink".

Author: keithbriggs

lib/matplotlib/colorbar.py

@@ -52,7 +52,7 @@
     *fraction*    0.15; fraction of original axes to use for colorbar
     *pad*         0.05 if vertical, 0.15 if horizontal; fraction
                   of original axes between colorbar and new image axes
-    *shrink*      1.0; fraction by which to shrink the colorbar
+    *shrink*      1.0; fraction by which to multiply the size of  the colorbar
     *aspect*      20; ratio of long to short dimensions
     *anchor*      (0.0, 0.5) if vertical; (0.5, 1.0) if horizontal;
                   the anchor point of the colorbar axes