Write ADR for identity vs location

[handrews]

As part of the larger discussion on referencing and imports (#72, #73), @darrelmiller suggested deciding on using IRIs as identifiers rather than locators as a first step. Part of the context is his discussions with his team around the impact of using $ref URLs as strict locators that must be read separately each time, plus the complexity of how to write changes back to such a separately-loaded reference that may be loaded in many different (possibly somehow conflicting) places within the OAD.

[handrews]

This is related to the OASComply reports and I might start by adding a supplementary report there as it has impacts on Moonwalk, OAS 3.x, and OASComply. Then I'll link from an ADR that addresses the Moonwalk-specific concerns.