The problem I'm trying to solve:
Since the snap is no longer recommended, it might make sense to simply combine the Debian and Ubuntu instructions, since Ubuntu is a Debian derivative anyway, it's already available in the repositories, and the instructions work predictably.

If I ever find a tool without a specific Ubuntu package, I just use the Debian ones.

How I imagine hub could expose this functionality:

ant@veil:~/Projects$ sudo apt install hub
[sudo] password for ant: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  xsel
The following NEW packages will be installed
  hub xsel

This would just be a readme update. Happy to open a PR if people think this is a good idea.