Create contributing.md for contributors to follow

[ivanchubb]

I'd like to help out, but unsure what styleguide to follow, where the priorities are with this project and where to start.

[SciLor]

I am afraid we don't have a real style guide or a nice backlog. Some items are in the issues list, but the rest are just ideas we get ourselves or by users. Regarding the style: Just try to blend in, use the auto format activated for vscode. If you need to change something in a lib like cyclone, copy the original into our source folder, edit the makefile and disable autoformat when editing the file. If you are unsure, feel free to contact us via telegram or open a discussion here.