5.0.4 - Remove slug requirement, add URI override

• Now uses ID's to pull in documentation entries, so your documentation's entries no longer require URLs, or do they need to be public
• If you override the name of the plugin (to say Admin Guide from User Manual), the url used to stay the same (/admin/usermanual). You can now override this to be a URI segment of your choosing, ie /admin/admin-guide if you so choose.