Add option to print command to standard output

[telotortium]

I use llm cmd because it takes care of the prompting to extract just a command from the LLM. Sometimes I don't want to edit and run the command, but just copy it. I can always just manually copy and paste, but it might be nice to use this from a keyboard shortcut or something like that, in which case the readline interface gets in the way.

Neither llm cmd ... </dev/null nor llm cmd ... | cat works as a workaround right now.