throw an error when requesting a non-existing theme/category combination
add a README file
remove $VERSION from source

because the distribution is built with Dist::Zilla
give the total number of themes when answering 'themes?'
use a single Acme::MetaSyntactic object for the class

the object is mostly used to check for theme existence
enforce the limit when asked for all items in a theme
Changes for version 1.002