Add dependencies to README and/or install.sh

[stereoplegic]

I'm on Neon (Ubuntu 20.04 base) and having to troubleshoot install.sh and the una command itself though command not found errors and the like (e.g. jq, asciidoctor). Now it looks like I need to hunt down various python deps, as neither una install nor una search are returning anything useful. Even worse, it's hard to tell if these are exclusive to una or also due to a lack of installed makedeb dependencies.

Can these various dependencies be added to the README or some other doc (and ideally, to install.sh as well)?