mapping GSC historical terminology and LinkML metaslots

[mslarae13]

discussed at the 2025 meeting working session
It would be useful to map the GSC historical terms (like description, structure comment name, structured pattern, etc) and the LinkML metaslot for a slot/term

Specifically, we need to provide the structure of the information.
For example, adding {color} when that doesn't yet exist requires additional work to provide the functionality of what's in the {}.

[mslarae13]

#944

https://github.com/GenomicsStandardsConsortium/mixs/blob/464dc38a6826fb7cef5e5cef41d56ac088943be0/src/docs/slot_specifications.md

[mslarae13]

@lschriml

[jfy133]

Note this PR also includes a full 'specification' document that describe how each MIxS term and the equivalent LinkML slot version of each term should 'look like'