Created by: uginroot
Fix border-radius and border for childrens .input-group
Added support .form-control, .btn-group > .btn, .form-control, .custom-file, in .input-group-append and .input-group-prepend .
Added support .input-group-text in .input-group
Added support .input-group-between https://github.com/twbs/bootstrap/issues/25120
Added an examples to the documentation