Return whisper version in cli or json output?

[pautri]

It doesn't look like the cli has an option to return the version number. It's possible to get it indirectly with python, but it would be useful to have a -v or --version argument, in my opinion.

Even nicer would be to have a sort of "metadata" section in the json output with the Whisper version that produced it as well as any arguments that were passed. Given the continuous development and improvement of Whisper, I think it's important to keep track of this information if you produce a lot of transcripts, in case you want to redo them later with an improved version or different settings. One could of course do this bookkeeping somewhere else, but why not have it as part of the output.