Fix typo in editor guide intro

docs/editor_manual/getting_started.rst

@@ -4,7 +4,7 @@ Getting started
 The Wagtail demo site
 _____________________
 
-This examples in this document are based on `Torchbox.com <https://torchbox.com>`_. However, the instructions are general enough as to be applicable to any Wagtail site.
+The examples in this document are based on `Torchbox.com <https://torchbox.com>`_. However, the instructions are general enough as to be applicable to any Wagtail site.
 
 For the purposes of this documentation we will be using the URL, **www.example.com**, to represent the root (homepage) of your website.