Minor CSS issue with fixed graphic in scroller

[lcyraphael]

Describe the bug There's some extra whitespace in the right margins in the scrollytelling template. This introduces a horizontal scroll bar across the whole page which shouldn't be there.

To Reproduce Steps to reproduce the behavior:

1. idyll create
2. Pick scrollytelling
3. idyll

Expected behavior Some overflowing margin on the right, which I think is caused by the fixed graphic in the scroller.

Screenshots

Desktop (please complete the following information):

• Windows 10
• Firefox, Chrome, Opera
• Idyll v4.10.1

Fix I think the below fixes it. If someone can verify it's not a breaking change, that'd be great 😄

.idyll-scroll-graphic {
  overflow: hidden;
}

[mathisonian]

Closing as this was fixed in #619