Add badges

[Fetz]

I should add some more badges:

• amazon wishlist (see https://github.com/IonicaBizau/emoji-unicode-map)
• npm version (see https://github.com/facebook/react/)
• PR welcome (see https://github.com/facebook/react/)
• add some quality badge but since bithound is dead I should investigate a bit what to use:
  1. https://codeclimate.com/quality/
  2. https://www.sonarqube.org/
  3. https://deepscan.io/home/
  4. command line tool? https://github.com/mre/awesome-static-analysis#javascript