Add a "whats_new" entry for the new figure.title* rcParams.

Author: wavexx

doc/users/whats_new/rcparams.rst

@@ -4,3 +4,10 @@ Added "legend.framealpha" key to rcParams
 Added a key and the corresponding logic to control the default transparency of
 legend frames. This feature was written into the docstring of axes.legend(),
 but not yet implemented.
+
+
+Added "figure.titlesize" and "figure.titleweight" keys to rcParams
+``````````````````````````````````````````````````````````````````
+
+Two new keys were added to rcParams to control the default font size and weight
+used by the figure title (as emitted by ``pyplot.suptitle()``).