[yocto] Adding ptest to the manual

[Björn Stenberg]

Hi.

I was reminded during the last YPTM call that it would probably be good to write something about ptest in the manual before release.

I have written a page in the wiki about it (https://wiki.yoctoproject.org/wiki/Ptest) but I'm not sure how to go about adding a chapter to the manual. Are you using any specific tool or do you edit the xml manually? Where do you think a section about ptest would fit into the manual?

-- 
Björn