There are probably dozen of possible books, but I think this one matches your description perfectly: https://www.goodreads.com/book/show/34927405-living-docume

There are probably dozen of possible books, but I think this one matches your description perfectly: https://www.goodreads.com/book/show/34927405-living-documentation https://www.goodreads.com/book/show/34927405-living-document... Just for reference, here is a classic about writing in general: https://www.goodreads.com/book/show/53343.On_Writing_Well https://www.goodreads.com/book/show/53343.On_Writing_Well