Update index.md

Author: robguthrie

en/src/user_manual/polls/inviting_people/index.md

@@ -28,7 +28,7 @@ However if the poll is within a thread, they will also be able to see the thread
 
 This is useful if you have a situation where only some people in the group should have voting rights, but you want the entire group to be able to see proposals. 
 
-If you do this regularly, we recommend creating a subgroup called (for example) "Voters subgroup" and adding everyone who has voting rights to this group. Now create a proposal within your parent group, and select "Only invited people can vote", then when inviting people, enter the name of the voters subgroup.
+If you do this regularly, we recommend creating a subgroup called (for example) "Voters subgroup" and adding everyone who has voting rights to this subgroup. Now create a proposal within your parent group, and select "Only invited people can vote", then when inviting people, enter the name of the voters subgroup.
 
 ![seleting invited people only](invited-people-only.png)
 ![inviting voters subgroup](invite-voters-subgroup.png)