Update Report Docs

Having this as a separate document to the existing endpoints/reports/clients.md is inconsistent with the other documentation. For example, take a look at https://github.com/resourceguru/api-docs/blob/master/endpoints/projects.md. In there, you will find documentation on both of these in one document:
GET /v1/:subdomain/projects returns an Array of Active Projects.
GET /v1/:subdomain/projects/archived returns an Array of Archived Projects.