Re-com should not install custom scrollbars globally

[johanatan]

The "modern" auto-disappearing scrollbars which one gets for free on Chrome on Mac OS X (for example) are preferred by most [modern] users. Is it possible to make hijacking that an option rather than the default?

[Gregg8]

For this feature, we'd be prepared to accept a PR. I imagine the scroll bar styles would be moved from re-com.css to another CSS file (re-com-scrollbars.css ?), or perhaps you have other thoughts on how to achieve this without making it a breaking change.