Switch from purl to agora URL for support

Summary:
They said purl was permanent URL.
They give control of purl to Internet Archive.

They said Internet Archive knows better.
Internet Archive gives anyone a free way to register an existing domain.

They said purl was permanent URL.
Internet Archive software overwrote previously assigned namespaces.

Test Plan: Browse URL

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D2244