[yocto] HOW DO I - new one added for EMGD and Crownbay

[jfabernathy]

I just added and EMGD example to the How Do I in the wiki.

In my opinion, we need to think about breaking this one big edit up into 
individual How Do I's.  It would simplify editing and make getting to 
the individual How Do I's much easier and quicker.

I don't know how to do that, but I think it needs doing.

Jim A