add backers&sponsors to readme (#419)
add backers&sponsors to readme (#419)

Now,  your backers/sponsors on Open Collective will appear automatically on your readme. 
This is how it'll look: https://github.com/webpack/webpack#backers
Also add badges. 
More info: https://github.com/opencollective/opencollective/wiki/Github-banner
developit/preact,neeharv/preact,gogoyqj/preact,developit/preact,neeharv/preact