Update index.html to correct alphabetical order (#4256)

Switching the position of User Inactivity and User Interface to make
them listed alphabetically.

This new PR is isolating one of the files changed in
#4122

Author: mbgower

guidelines/index.html

@@ -759,10 +759,10 @@ <h1>Glossary</h1>
                 <dt data-include="terms/20/user-agent.html" data-include-replace="true"></dt>
 
                 <dt data-include="terms/20/user-controllable.html" data-include-replace="true"></dt>
-
-                <dt data-include="terms/20/user-interface-component.html" data-include-replace="true"></dt>
 
             	<dt data-include="terms/21/user-inactivity.html" data-include-replace="true"></dt>
+                
+                <dt data-include="terms/20/user-interface-component.html" data-include-replace="true"></dt>
 
                 <dt data-include="terms/20/video.html" data-include-replace="true"></dt>