Hi,
I really liked the way the comments are implemented on this website https://medium.com/the-physics-arxiv-blog/5e7ed624986d
Basically the comments are associated to each paragraph, and a little number appears next to it. When clicking it, it displays the comments. I can imagine that it would also make sense on wikipedia, where most comments are related to specific points in the text.
The article itself is also worth a read ;-)
Cheers, Micru