Customising Help Center

Customising Help Center

Hi

I don't think it is possible to add custom pages to help center? 
We'd like to use this as a customer portal with support tickets, FAQ/Guides, Billing and contracts. 
Is there any plans to add a feature like this or an alternative way to do it other than creating a whole new site? We like the help center and just wanted to add these 2/3 custom pages atop the rest of the features in help center.