Bootstrap v4 beta - Documentation shows native font stack "system-ui" but it has been removed

Created by: dotnetshadow

The documentation for native fonts needs to be updated to remove system-ui https://v4-alpha.getbootstrap.com/content/reboot/#native-font-stack

// Chrome >= 56 for OS X (San Francisco), Windows, Linux and Android
system-ui,

A recent commit shows that this font is no longer used https://github.com/twbs/bootstrap/issues/22328

When looking at the dist/css/bootstrap.css it is indeed gone

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 1rem;
  font-weight: normal;
  line-height: 1.5;
  color: #212529;
  background-color: #fff;
}