Custom stacked checkbox label stretches to full width

Created by: jacobmllr95

Operating system and version: Any Browser and version: Any Test case: https://getbootstrap.com/docs/4.0/components/forms/#stacked

As seen in the picture above, the label of a stacked checkbox stretches to the full with of the parent container. This can cause issues when a user clicks far right from the visible label and accidentally toggles a checkbox or radio.

A simple fix would be to set align-items for the custom-controls-stacked container to flex-start (see picture below).