Add support to convert between gherking and markdown format

[laeubi]

🤔 What's the problem you're trying to solve?

If one want to switch to the markdown format this needs to be done in some external process

✨ What's your proposed solution?

It would be good to have an option to convert a file from one to another format e.g. using https://github.com/cucumber/gherkin-utils

this should then include rename the file to file.feature.md

⛏ Have you considered any alternatives or workarounds?

No response

📚 Any additional context?

No response