fix whatsnew formatting

Author: RDaxini

docs/sphinx/source/whatsnew/v0.11.2.rst

@@ -34,6 +34,7 @@ Documentation
 * Explained how to write docstrings for new functions in :ref:`example-docstring`
   (:discussion:`2081`, :pull:`2254`)
 * Added the following variables to the :ref:`nomenclature` page:
+
     - `spectra` and `spectra_components` (:issue:`2150`, :pull:`2264`)