[Fix] Scroll Setting, correct heading and apply "by" label

- Adding `<h5>` in HTML template to apply a group heading for Scroll Setting, which is consistent with other component group styling
- Added new label value in translation.json for `scroll.by.label` and applied in HTML template
Merge pull request #171 from stulees/bug/scroll-setting-heading

[Fix] Scroll Setting, correct heading and apply "by" label