Move terms types (document types) to their own repository

[MattiSG]

Declare document types as a peer dependency of the Core.

This will enable:

• Proper dependency management instead of updating lockfile (see https://github.com/OpenTermsArchive/france-declarations/issues/350) or triggering Core major updates on breaking document type changes.
• Different versions of document types with full Core compatibility.
• Scoping documentation and discussions in a dedicated repository.
• Independent release schedule.

Name the repo @opentermsarchive/terms-types and publish it on NPM as @opentermsarchive/terms-types.

[MattiSG]

Impact on other services: https://github.com/OpenTermsArchive/terms-types/pull/3#issuecomment-1346165741