fix typo

content/contribute.rst

@@ -137,10 +137,10 @@ Run the command ::
 
     git format-patch origin/master
 
-This will create “patch” file for each commit on your branch.  Now simply send
-these patches as email attachments to kwant-devel@kwant-project.org, together
-with an explanation of your idea.  You do not have to be subscribed to the
-mailing list.
+This will create a “patch” file for each commit on your branch.  Now simply
+send these patches as email attachments to kwant-devel@kwant-project.org,
+together with an explanation of your idea.  You do not have to be subscribed
+to the mailing list.
 
 (Or, even better, use ``git send-email`` as shown in this `example of usage
 <https://kernel.org/pub/software/scm/git/docs/git-send-email.html#_example>`_