whatsnew corrections (#3494)

Author: max-sixty

doc/whats-new.rst

@@ -41,7 +41,7 @@ New Features
 - :py:meth:`Dataset.drop_sel` & :py:meth:`DataArray.drop_sel` have been added for dropping labels.
   :py:meth:`Dataset.drop_vars` & :py:meth:`DataArray.drop_vars` have been added for 
   dropping variables (including coordinates). The existing ``drop`` methods remain as a backward compatible 
-  option for dropping either lables or variables, but using the more specific methods is encouraged.
+  option for dropping either labels or variables, but using the more specific methods is encouraged.
   (:pull:`3475`)
   By `Maximilian Roos <https://github.com/max-sixty>`_
 - :py:meth:`Dataset.transpose` and :py:meth:`DataArray.transpose` now support an ellipsis (`...`)
@@ -120,6 +120,8 @@ Internal Changes
 - Run basic CI tests on Python 3.8. (:pull:`3477`)
   By `Maximilian Roos <https://github.com/max-sixty>`_
 
+- Enable type checking on default sentinel values (:pull:`3472`)
+  By `Maximilian Roos <https://github.com/max-sixty>`_
 
 .. _whats-new.0.14.0: