Update comments.md

Closes https://github.com/gohugoio/hugo/issues/6819

content/en/content-management/comments.md

@@ -53,7 +53,6 @@ There are a few alternatives to commenting on static sites for those who do not
 
 * [Static Man](https://staticman.net/)
 * [Talkyard](https://www.talkyard.io/blog-comments) (Open source, & serverless hosting)
-* [txtpen](https://txtpen.github.io/hn/)
 * [IntenseDebate](https://intensedebate.com/)
 * [Graph Comment][]
 * [Muut](https://muut.com/)
@@ -64,12 +63,6 @@ There are a few alternatives to commenting on static sites for those who do not
 * [Commento](https://commento.io/) (Open Source, available as a service, local install, or docker image)
 * [JustComments](https://just-comments.com) (Open Source, available as a service, can be self-hosted)
 
-<!-- I don't think this is worth including in the documentation since it seems that Steve is no longer supporting or developing this project. rdwatters - 2017-02-29.-->
-<!-- * [Kaiju](https://github.com/spf13/kaiju) -->
-
-<!-- ## Kaiju
-
-[Kaiju](https://github.com/spf13/kaiju) is an open-source project started by [spf13](https://spf13.com/) (Hugo’s author) to bring easy and fast real time discussions to the web.
 
 Written using Go, Socket.io, and [MongoDB][], Kaiju is very fast and easy to deploy.