A seasoned programmer's take on Nim's docs

[geohuz]

I found the offical documentaion lack of discussing on "more" advanced topic 
like when to use `ref object` versus `object`, if you look at the official 
tutorial II, they all convered by simple description and example, but for 
beginner to grasp their usage it is better to give some rational talk. This 
also happens to concept, it is better to provide narrative paragraph to 
explain, or provid a link on wikipedia of parametric polymophism. I believe the 
"ref object" and "object" are more important as sooner or later people start to 
use it to model data structure. (I know their discussion acutally exist in the 
Nim for Beginners video but I'm still insist it should be stated in official 
tutorial as text)