Add apostrophe

docs/editor_manual/new_pages/inserting_links.rst

@@ -12,7 +12,7 @@ Whichever way you insert a link, you will be presented with the form displayed b
 
   * Internal link: A link to an existing page within your website.
   * External link: A link to a page on another website.
-  * Email link: A link that will open the users default email client with the email address prepopulated.
+  * Email link: A link that will open the user's default email client with the email address prepopulated.
 
 * You can also navigate through the website to find an internal link via the explorer.