Update README.md and add LICENSE

[kristoforsalmin]

Hi there,

I want to visually improve our repo a tiny bit, hope you don't mind 😄 Please let me know if it makes sense or if I'm missing something.

README.md

• Update badges. Currently click on them leads us nowhere (except build one). Probably it'd be nice to use David DM for dependencies and I'm pretty sure there's something out there for npm releases as well.
• Update code block in Install section by adding yo dependency (npm install -g yo generator-rammevaerk). Or maybe make a separate step for Yeoman installation. I think, this will save time if user hasn't used it before.
• Remove $ from code blocks as it makes it harder to copy-paste. Fix code block for $ yo doctor.
• Minor typo here and there.

LICENSE

Probably it'd be a good idea to add LICENSE file, so repo will get this nice license indicator:

Thanks

[mi2oon]

What are we waiting for... I don't mind at all it all sounds good so lets make it look good 😎