You have to get advice from the PhoneGap documentation or some PhoneGap
forum. This has nothing to do with jQuery Mobile. Nor does it have
anything to do with Dreamweaver.
You can build a PhoneGap project of any size if you install the
development tools on your desktop. The Adobe online build service has
limits. If you have a small project, the build service let's you avoid
having to install the tools on your desktop.