First version of Egor's article…

[dutchcelt]

Please don't hesitate to let me know if there are any issues. I may reread it tomorrow in case it needs some fine-tuning. If that is okay?

This article has footnotes. This may not work. I can remove them if necessary.

[matuzo]

Thanks a lot, looking forward to reading it! :)

I'm merging it into another branch to make it easier for the reviewers. If you only have small changes please wait until we're finished reviewing. If it's big changes, let me know and I'll merge the changes again.