feat: Export comapeo-schema

[RangerMauve]

As we discussed, this should make versioning schema along with core easier on downstream dependants. We'll need to update the schema related imports to pull from @comapeo/core/schema

Should I add more docs somewhere before merging?

[RangerMauve]

@achou11 Should this be a .js export, too, then?

[achou11]

@achou11 Should this be a .js export, too, then?

I would say so yeah, for the sake of consistency

[achou11]

Need to update the include field in tsconfig.npm.json to have "src/schema.js" so that the relevant types file is emitted.

Also (because I'm not sure): do we only want to export the types from schema or is it preferable to re-export the entire module? Doing the former would require additional changes.

[RangerMauve]

I think re-exporting just the root of schema should be enough judging by how stuff is being imported in mobile and desktop

https://github.com/search?q=repo%3Adigidem%2Fcomapeo-mobile%20%22%40comapeo%2Fschema%22&type=code

https://github.com/search?q=repo%3Adigidem%2Fcomapeo-desktop%20%22%40comapeo%2Fschema%22&type=code

https://github.com/search?q=repo%3Adigidem%2Fcomapeo-cloud%20%22%40comapeo%2Fschema%22&type=code