Mention versioned contexts and add a changelog to w3.org/ns/activitystreams #659
Description
https://www.w3.org/ns/activitystreams is the namespace for terms defined in activity streams 2.0 (and it is also ambiguous wrt the ontology vs the context, as #416 points out, but this is a separate issue for now).
on that page's html representation, there is no link to, or any mention of, the versioned contexts currently available at https://www.w3.org/ns/activitystreams-history -- nor any changelog to note when term definitions have been changed.
changing term definitions changes the semantics of those terms, and any documents authored using certain semantics can suddenly have their meaning changed from underneath them if the definition changes. in practice, this means that contexts should be frozen to some extent, and this can be observed in other context documents like https://w3id.org/security/v1 vs https://w3id.org/security/v2. any semantic drift over time can be fixed by updating older documents to use newer contexts, instead of having the context updated and thus changing the meaning of the document inadvertently.
Proposal
- Add a "Changelog" section to ns/activitystreams
- Merge in the content of ns/activitystreas-history
- Add descriptions of what changed in each version