During the transition to Metrics Platform-style schemas, the information in today's schemas will be split into (1) standard fields and (2) non-standard fields (aka "bespoke" or "custom"). We want to ensure that none of the existing information about any field type is lost, and to ensure that there is a mapping from the fields in the legacy version to the fields in the Metrics Platform version, so that we can port documentation and get used to any changes.

This task comprises the creation of a script and convention for doing this.

• Create a script to split legacy-style metrics into (1) a mapping file (2) a non-standard fields data dictionary fragment, and (3) a Metrics Platform stream configuration, given a key
• Create a way for the outputs of these scripts to be stored and displayed.