Is your feature request related to a problem? Please describe.
I'm looking for the possibility to generate an SSH key (private and public pair) in a Kubernetes secret.

Describe the solution you'd like
A dedicated generator would be perfect, with an option for an algorithm maybe (rsa or ed25519), and size of the key (for rsa).

Describe alternatives you've considered
https://github.com/mittwald/kubernetes-secret-generator/ works fine, but it is limited to RSA only, and I would prefer ESO as a single service to handle secrets.

Eventually I consider to build dedicated REST service to use with webhook-based ESO generator.