Prepare for open source

[commjoen]

• [x] - create contribution guide (issue template + pr template)
• [x] - create better readme (intro, howto, contributing, thanks to @sushi2k , Xebians and @clviper)
• [x] - reassure proper thanks to Geerlingguy for awesome plugins
• [x] - reassure other licenses (and tell which items are currently installed)
• [x] - create automated build with checks
• [x] - note that this is still a Poc and can use a lot of help!
• [x] - have slack integration (done)
• [x] - Finish #2