fix: replace var keyword with const/let (#11512)

public/research-notify.js

@@ -3,7 +3,7 @@
 //Nice tips on jquery inclusion etc here: http://www.smashingmagazine.com/2010/05/23/make-your-own-bookmarklets-with-jquery/
 
 function getSelText() {
-  var SelText = '';
+  let SelText = '';
   if (window.getSelection) {
     SelText = window.getSelection();
   } else if (document.getSelection) {
@@ -17,12 +17,12 @@ function getSelText() {
 (function(){
 
   // the minimum version of jQuery we want
-  var v = "1.3.2";
+  const v = "1.3.2";
 
   // check prior inclusion and version
   if (window.jQuery === undefined || window.jQuery.fn.jquery < v) {
-    var done = false;
-    var script = document.createElement("script");
+    let done = false;
+    const script = document.createElement("script");
     script.src = "http://ajax.googleapis.com/ajax/libs/jquery/" + v + "/jquery.min.js";
     script.onload = script.onreadystatechange = function(){
       if (!done && (!this.readyState || this.readyState == "loaded" || this.readyState == "complete")) {
@@ -49,4 +49,4 @@ function getSelText() {
     })();
   }
 
-})();
+})();