Add an option to `step ca certificate` to output the leaf and intermediate chain in separate files.

[dopey]

Some clients don't accept a full chain. It would be easier to work with separate files in those cases.

[aliamerj]

@dopey Is this Issue still on ? if so can I do it ?

[dopey]

Hey @aliamerj 👋. This issue is definitely still on (in fact we were discussing it earlier today during an open source meeting).

We'd love to have your help with it! We were thinking that the way to implement this would be an additional flag (called intermediate-file), which, when passed in, would cause the intermediate chain to be written to the specified file (and not to the leaf cert file). Let me know if you have any questions :)

[aliamerj]

Hey @dopey 👋 Thanks for the clarification and the warm welcome! I'll start working on this and will reach out if I have any questions 😊