The "Disqus" extension inserts a Disqus comment thread in your templates. Use it by simply placing the following in your template:
{{ disqus() }}
To include the current page's title, pass it as a parameter:
{{ disqus( record.title ) }}
In your overview and listing pages, you can include a link to the comments, where the 'Comment' text will be replaced with the actual amount of comments.
<a href="{{ disquslink(record.link) }}">Comment</a>
This is assuming record is the record. If not, replace it with the appropriate variable name.