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