Provide install instructions for Debian and Ubuntu and get rid of the script that asks users to pipe into bash #1126

Asking users to run a script by piping it into sudo bash is absolutely insane, sorry. This should never be how anyone recommends users install their package. Please provide clear instructions for installing soundnode on Debian and Ubuntu and get rid of the script for installing soundnode.

I tried to figure out how to install soundnode without your script, but https://packagecloud.io/JonasGroeger/soundnode/ubuntu/ isn't even a valid url. There's nothing there. https://packagecloud.io/install/repositories/JonasGroeger/soundnode/config_file.list?os=ubuntu&dist=bionic&source=script tells me that should be the repo url, but when I navigate there in a browser, I'm greeted with an error page.