DataTransfer.{effectAllow,dropEffect} should be vars

Author: japgolly

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

@@ -3805,15 +3805,15 @@ trait DataTransfer extends js.Object {
  *
  * MDN
  */
- def effectAllowed: String = ???
+ var effectAllowed: String = ???
 
  /**
  * The actual effect that will be used, and should always be one of the possible values
  * of effectAllowed.
  *
  * MDN
  */
- def dropEffect: String = ???
+ var dropEffect: String = ???
  /**
  * Remove the data associated with a given type. The type argument is optional. If the
  * type is empty or not specified, the data associated with all types is removed. If