ATLAS VRA Technical Manual

This is a technical manual to the ATLAS Virtual Research Assistant and history of the development of the VRA. It is mostly a resource for developers and eyeballers, although for external collaborators it can also be supplementary information on the development of the VRA - information that either does not fit in the paper or is not part of a public data release. Version 2 updates: Fixed a typo in the current VRA garbage policies (1.0 not 1.5) and updated the dev check list to upgrade the VRA as we just tested this check list when implementing VRA v1.1 in production.