Update documentation

[Lucky-Loek]

I've found myself looking through your commits and issues often, because you haven't always updated the docs. No biggie, hope you won't mind I've updated the docs to the current version (1.14)

And I've added a little contributing guide, so the Issues and PR section will get a little cleaner ;)

EDIT: StyleCI can't access my fork my fork for some reason, that's why it errors.

[jeroennoten]

Wow! Thank you very much! I indeed did not always update the docs. I will try to do that from now on when I add new features.

At some point, I want to move over the docs to some other, more managable place, such as Github Wiki, or some other documentation service. But for now, this is a very good improvement of the current docs.

[Lucky-Loek]

Oh I don't really mind. You write clean code and commit clearly, so it's not hard to understand what's new. I'd be glad to help if you need it :)