I've made it in ePub format and then converted to Mobi with Calibre.
It has the same formatting as in webpage (hyperlinks, font style...) and a full Table of Contents plus some tutorials and some useful official's blog entries.
Construct 2 Manual (ePub)
Construct 2 Manual (Mobi)
Tell me if you find errors or have any suggestion.
Added new "Performance Tips" section.