Added loudness entries to functional.rst and transforms.rst

Author: bshall

docs/source/functional.rst

@@ -69,6 +69,11 @@ resample
 
 .. autofunction:: resample
 
+loudness
+--------
+
+.. autofunction:: loudness
+
 
 :hidden:`Filtering`
 ~~~~~~~~~~~~~~~~~~~

docs/source/transforms.rst

@@ -90,6 +90,13 @@ Transforms are common audio transforms. They can be chained together using :clas
 
   .. automethod:: forward
 
+:hidden:`Loudness`
+-------------
+
+.. autoclass:: Loudness
+
+  .. automethod:: forward
+
 :hidden:`Feature Extractions`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~