A good example of the style of documentation that makes things difficult for beginners is the 'Iterators and the For statement' section in the Nim manual. From a beginners perspective this might be better presented as two sections, one about the For statement, the second about iterators and their use in for loops to enable 'for each' style loops.
There is no mention of 'For' in the contents under the 'Statements and expressions' part of the contents column. The 'for' section might be simpler by starting with the use of countup/countdown to closer link to for loops in other languages Then a discussion on how to implement the equivalent of for each using iterators. Just an observation.
