Add whatsnew entry.

Kiv · Kiv · commit 29343d7649c7 · 2017-05-26T12:55:38.000-03:00
diff --git a/doc/source/whatsnew/v0.21.0.txt b/doc/source/whatsnew/v0.21.0.txt
@@ -75,7 +75,7 @@ Removal of prior version deprecations/changes
 
 Performance Improvements
 ~~~~~~~~~~~~~~~~~~~~~~~~
-
+- :class:`pandas.HDFStore`'s string representation is now faster and less detailed. For the previous behavior, use ``pandas.HDFStore.info()``. (:issue:`16503`).
 
 
 .. _whatsnew_0210.bug_fixes:
