Add instructions on how to edit COB

[cmungall]

Do I update the edit.owl, a google sheet, or a tsv?

[jamesaoverton]

You edit src/ontology/cob-edit.owl and src/ontology/components/cob-to-external.tsv (a SSSOM table).

Building on our work at the COB workshop, Sebastian and I will create a branch/PR that uses a ROBOT template TSV file. We'll link to that here when it's ready. For a small ontology like COB, I think that's a good approach, but we'll have a community discussion when we get there.