When something is partially implemented, only describe the implemented bit, or flag it if this is clear

[sandreae]

For things like KeyGroup and SecretGroup which are implemented in p2panda-rs but not used in aquadoggo yet then it makes sense to include them in the spec with a little label saying not supported by aquadoggo yet. But when a feature is partially implemented, and only exists in aquadoggo I think it could be a little confusing to specify it unless we can easily mark which bits are/are not implemented. For example, the filtering in the graphql client api.