ITE-9: Route to acceptance

[adityasaky]

ITE-9's been in draft status for some time now, and has also been used to propose some new predicates, most recently the vuln scan results one. The attestation framework spec has some guidance on proposing new predicate specifications but also points to ITE-9. I propose moving the template for a predicate proposal and so on into the in-toto/attestation and moving forward with ITE-9's acceptance. I believe the ITE has served its purpose in establishing a process for defining predicates and we can now carry that forward in the attestation framework without requiring the ITE to be a living document.

[adityasaky]

cc @in-toto/attestation-maintainers

[JustinCappos]

I support this move.

[marcelamelara]

For reference, here are the current guidelines in in-toto/attestation, in case any of the ITE editors want to review before accepting ITE-9.