Add instructions on relative firmware for the timing manager

Abstract

To do: add one sentence description of what needs to happen

Context

There are instructions for apps and boards that don't mention the Timing Manager in AMDC docs

Approach

Update the Testboard docs to remind the user to enable any timing manager devices. For the case of the Testboard, without enabling the ADC in the Timing Manager, none of the tests will pass.

Close this issue with a PR that:

• Updates the AMDC docs to include these instructions.