[TIDOC-1157] Modifications to support platform docs

Build platform docs.
~~~
export outdir=$TI_ROOT/doctools/dist/platform/latest
mkdir -p $outdir
sh deploy.sh -o modules -g htmlguides-latest -a guides-enterprise -d $outdir -t "Appcelerator Platform - Appcelerator Docs"
~~~~
The Titanium Quick Start guide should be replaced by the Appcelerator Platform Quick Start guide.

Build titanium docs.
~~~
export outdir=$TI_ROOT/doctools/dist/titanium/3.0
mkdir -p $outdir
sh deploy.sh -o modules -g htmlguides-latest -d $outdir
~~~

The first link in the Titanium Quick Start guide should point to the Appcelerator Platform Quick Start guide.