Update cf/docstring/docstring.py

Co-authored-by: Sadie L. Bartholomew <[email protected]>

Author: davidhassell

cf/docstring/docstring.py

@@ -636,7 +636,7 @@
                 ==============  ======================================
                 *mode*          Description
                 ==============  ======================================
-                Not provided            If no positional arguments are
+                Not provided     If no positional arguments are
                                 provided then assume the
                                 ``'compress'`` mode of operation with
                                 no halo added to the subspaced axes.