DOC: Added limit_area to whatsnew

Author: WBare

doc/source/whatsnew/v0.21.0.txt

@@ -24,6 +24,7 @@ New features
   <https://www.python.org/dev/peps/pep-0519/>`_ on most readers and writers (:issue:`13823`)
 - Added `__fspath__` method to :class`:pandas.HDFStore`, :class:`pandas.ExcelFile`,
   and :class:`pandas.ExcelWriter` to work properly with the file system path protocol (:issue:`13823`)
+- Added `limit_area` parameter to `DataFrame.interpolate()` method allowing further control of which NaNs are replaced (:issue:`16284`)
 
 .. _whatsnew_0210.enhancements.other: