RStudio now defaults to `ed25519` algorithm for ssh keys

[jacpete]

Caveat mentioned at https://happygitwithr.com/ssh-keys#from-rstudio no longer applies. RStudio defaults to keys with the ed25519 algorithm.

Caveat: RStudio only looks for a key pair named id_rsa and id_rsa.pub. This makes sense, because historically that has been the most common.

However, these days both GitHub and GitLab are encouraging users to generate SSH keys with the Ed25519 algorithm, which results in a key pair named id_ed25519 and id_ed25519.pub. At the time of writing, RStudio will not display such a key pair, which can be confusing. Therefore, it’s probably a good idea to also check for existing keys in the shell.