This is might not be formally released soon, but it is a book in development. It is written in English by a non-native speaker of English, which might throw some people off, but it is certainly an extremely valuable resource and a lot of effort has been dedicated to it.
<https://ssalewski.de/nimprogramming.html> The development repo is <https://github.com/StefanSalewski/NimProgrammingBook>
