Back to Top button - Githubissues

We need a "Back to Top" button on the end of each document.

It should appear only after the page was scrolled down a bit, so a bit of JS code needed.
It should have position: fixed and appear somewhere in bottom right corner.
It could be an arror pointing up (↑ will be fine) in a circle.
Would be nice to animate scroll when clicked, but not essential for MVP.

kobotoolbox / docs