Fix style

doc/source/development/contributing_documentation.rst

@@ -79,7 +79,7 @@ Some other important things to know about the docs:
   ``Attributes`` and ``Methods`` section for the class, leading to a redundant
   specification. To prevent this duplication, we have a custom autosummary
   template ``_templates/autosummary/class.rst`` that will generate class pages
-  without any method or attribute documentation. 
+  without any method or attribute documentation.
 
   For some classes we only want to document a subset of APIs. For those, the
   you should include an ``Attributes`` and ``Methods`` section in the class