Add missing usage statements for priority AEs

[dosumis]

Summary table showing shorthand, labels, usage statements and defs for AE relations (some deprecated relations present): https://docs.google.com/spreadsheets/d/10A3xFGAc9oAg4if5sBYVUQX1uPM8HXhbr6_nnUgToPc/edit#gid=0

CC @rachhuntley @RLovering

[dosumis]

Note to self - script here as GIST https://gist.github.com/dosumis/df81b9e4a0fc42cc9e27049d89920cd8

[dosumis]

Usage statements are designed to guide usage of relations in GO annotation rather than provide a general purpose, logically solid definition. They should follow the pattern:

"Use this relation to link an X to a Y where...Z." Usage statements don't necessarily cover all uses. Further clauses may be added: "This relation may also be used to link..."

[dosumis]

50% complete. (see notes on sheet)