Created by: MartijnCuppens
The small and large line-heights are the same for sm and lg components, so they can easily be dropped. I still left the ability to change the line-heights for buttons.
Fixes #28622 (closed) Fixes #28907 (closed)
Preview: https://deploy-preview-29271--twbs-bootstrap.netlify.com/docs/4.3/utilities/text/#line-height