Linked identities

[KyleMaas]

See %8jlwf9eZj75Qjd7zWrZnsd5hSdCP9nOlQ3u1m0mKy/c=.sha256

https://github.com/ssbc/ssb-identities

[arj03]

This is the existing approach to multiple identities, just have multiple keys. What meta feeds opens up is the ability to have multiple feeds with different purposes. So you could have a feed about hardcore development, one about family life etc. The difference between these two is that one is linked to a common identity while in the other they are not. Whether that is a good thing or not depends on the use case.