Add semantic major version readiness checklist

[aaronc]

Following up on some comments I made on discourse, I think we should have a small readiness audit for tagging go modules as v1.0 (or any major version. The basic steps I have in mind are something like:

• [ ] review (or re-review) https://go.dev/blog/module-compatibility so it's fresh in your mind
• [ ] read through the go docs of each package in the module on https://pkg.go.dev and address any issues, in particular:
  • [ ] should any functions take an options struct instead of positional params?
  • [ ] should any functions take variadic options?
  • [ ] should any interfaces have a private method to allow them to be changed in the future?
  • [ ] should any structs be non-comparable?

[julienrbrt]

Small update on this:

• We still haven't figured which semver we will go for modules (the one defined here won't work: https://github.com/cosmos/cosmos-sdk/blob/7b5d3e5/RELEASES.md#semver-dependencies)
• There was a proposal to add a build tag or a -consensus to convey the consensus version changes, but it doesn't play well with version order.

This is still something being discussed.