IE 11 detection + add warning div to body

ieDetection.js

//check for ie methods
var isIE11 = !!window.MSInputMethodContext && !!document.documentMode;

//start if ie
if (isIE11 == true) {
  //add tags to body to write scoped css
  document.body.className += " " + "internetExplorer ie11"
  //add div element to warn users that they are using an outdated browser
  window.document.body.insertAdjacentHTML( 'afterbegin', '<div class="oldIE">You are using an outdated Browser…</div>' );
}