Improve dashboard layout framework architecture design document based upon finalised approach

Problem to solve

With the creation of the Dashboard Customization Framework architecture design document, we have several areas that we were unsure of until we'd had a chance to implement the framework in code.

Creating the framework as code gives us an opportunity to validate our assumptions, as well as identify any unknowns and document them accordingly.

This issue should be used to update the design document once we have determined the approach we wish to take.

Improvements / Fixes

Edited by Jiaan Louw