How to add NetBeans update center to my NetBeans application updater

I have deployed a NetBeans platform application using the update center, which works very well.   It is based on NetBeans 8.0.2.  I have noticed that I've received updates to my NetBeans IDE from the NetBeans update center (such as git) but these updates are not appearing in my deployed NetBeans app.

I assume that I need to add a reference to the NetBeans Update Center to my layer.xml that describes the Services/AutoupdateType, but I can't see documentation on how to do that?  I see general discussion about adding multiple update center descriptions but not specifics about how to point to the NetBeans site.

Can you point me to the documentation or give me an example of how to do this?

Thank you very much.

Todd Stevenson