Improve Flashing Documentation

I have two ideas as to how to improve the flashing documentation.

- I could try to interpret the Windows instructions based on the pictures and Google Translate, and write it up in English.

- I also saw on the chat a work in progress CLI tool, which I could add to the central documentation as well.
(https://github.com/stschake/bl60x-flash)

Should I do either of these things?