Add code field to KeyboardEvent

Author: fndejan

dom/src/main/scala/org/scalajs/dom/KeyboardEvent.scala

@@ -54,6 +54,9 @@ class KeyboardEvent(typeArg: String, init: js.UndefOr[KeyboardEventInit])
 
   /** Returns the current state of the specified modifier key. */
   def getModifierState(keyArg: String): Boolean = js.native
+
+  /** Returns a string with the code value of the physical key represented by the event. */
+  def code: String = js.native
 }
 
 @js.native

dom/src/main/scala/org/scalajs/dom/KeyboardEventInit.scala

@@ -27,4 +27,7 @@ trait KeyboardEventInit extends UIEventInit with ModifierKeyEventInit {
 
   /** Sets value of KeyboardEvent.repeat. Defaults to false. */
   var repeat: js.UndefOr[Boolean] = js.undefined
+
+  /** Sets value of KeyboardEvent.code. Defaults to empty string. */
+  var code: js.UndefOr[String] = js.undefined;
 }