Created by: sts-ryan-holton
This PR adds a new .rounded-pill class as per MDO's comment on https://github.com/twbs/bootstrap/issues/26442 and also adds a new .btn-rounded class to the buttons component (https://getbootstrap.com/docs/4.1/components/buttons/)
Essentially, I've made a reusable mixin which is then applied to both the .rounded-pill and btn-rounded classes. I felt it wouldn't make sense to simply apply a .rounded-pill class directly to a .btn as MDO has mentioned in many conferences about creating modifier classes, it only makes logical sense to then create a .btn-rounded class to follow this structure.
This PR also updates the docs with these new classes
Hoping we can add this into Bootstrap 4.2, and hope to see it as a useful feature as I received positive community upvotes with this
Fixes #26442 (closed)