Based on https://marc.info/?l=openssh-unix-dev&m=160121534105667&w=2 , it is not recommended to use ssh-rsa any more. I'm not sure which of the 3 suggested alternatives should be used, but whichever is chosen should be compatible with GitHub (60-70% of the users) and Gitlab (30% of the users).

Additionally, I should probably document exactly what kind of keys are being generated so that people who are self hosting an SSH server can diagnose any issues.

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