One of the biggest disadvantages of static site generators is that they are static and can’t include comments.
There are multiples solutions to solve this problem. You could add a third party blog engine like Disqus, but this has the drawback of including a third-party tool with a bad privacy record in your website. Another solution would be to host an open-source alternative but this comes at the cost of a higher maintenance burden.
This seems to be relying heavily on the mastodon markup and prolly won’t work with other fediverse software.
EDIT: After looking more closely I realize all the markup was the author’s own markup, not the mastodon markup. As the author is using the Masto API, this should work with any software that implements that API. I still think this is not a good solution because it prioritizes mastodon over the rest of the fediverse. Comments from some people will be displayed, but not those of people using other software.