Fix typos in comments (select2#5336)

Author: timgraham

src/js/select2/dropdown.js

@@ -30,7 +30,7 @@ define([
   };
 
   Dropdown.prototype.position = function ($dropdown, $container) {
-    // Should be implmented in subclasses
+    // Should be implemented in subclasses
   };
 
   Dropdown.prototype.destroy = function () {

src/js/select2/dropdown/attachBody.js

@@ -156,10 +156,10 @@ define([
       top: container.bottom
     };
 
-    // Determine what the parent element is to use for calciulating the offset
+    // Determine what the parent element is to use for calculating the offset
     var $offsetParent = this.$dropdownParent;
 
-    // For statically positoned elements, we need to get the element
+    // For statically positioned elements, we need to get the element
     // that is determining the offset
     if ($offsetParent.css('position') === 'static') {
       $offsetParent = $offsetParent.offsetParent();

src/js/select2/results.js

@@ -339,7 +339,7 @@ define([
 
       var currentIndex = $options.index($highlighted);
 
-      // If we are already at te top, don't move further
+      // If we are already at the top, don't move further
       // If no options, currentIndex will be -1
       if (currentIndex <= 0) {
         return;