Improve installation setup for Linux

[jwerle]

Improve installation setup for Linux

[tournesolo]

Timely: I just tried installing on linux following your npm instructions and ran into a couple of issues. I'm documenting them here in case that helps update your install instructions (I don't need help or explanations, I know how to proceed).

So first, running npm i @socketsupply/socket -g and then ssc init as indicated in the install instructions, yields Command 'ssc' not found.

Finding the ssc command and using it explicitly, as in /usr/local/lib/node_modules/bin/ssc init then complains about error while loading shared libraries: libwebkit2gtk-4.1.so.0. This is because libwebkit2gtk-4.0-37 is installed (Debian buster).

You might want to tell users about putting ssc in the path when using the npm method, and you might also want to tell users which distributions you recommend (or tell them to check their libwebkit version when installing via npm). I hope that helps and good luck with this cool project!