Having the `<br>` tag in here, makes that for jackknifed plots, the ellipse opacity slider appears a couple lines after the other controls in the view tab, might be worth integrating these tags in the `_ELLIPSE_OPACITY_SLIDER`, `_VECTORS_OPACITY_SLIDER`, `_TAXA_LABELS_SELECTOR`, `_BIPLOT_VISIBILITY_SELECTOR`, etc strings in `format.py`.

To see what I'm referring to, check the view tab in the jackknifed example in the make_emperor folder.