Update index.js to correctly integrate diff as Date mathod

Update index.js to correctly integrate diff  as Date mathod

src/index.js

@@ -44,14 +44,10 @@ const diffDates = require('./diff-dates');
  * @param {string} date (type- String but Number for epoch, and Object for dateObject) - The date to be differed, in the format 'yyyy-mm-dd' or 'yyyy/mm/dd' or yyyy.mm.dd or dateString or dateObject or Timestamp(epoch).
  * @returns {DatesYMD} An object containing methods for date difference calculations.
  */
-export function config(Date) {
   Date.prototype.diff = function (date) {
     return diffDates(this, date);
   } 
-};
 
 // Export the DatesYMD class and equivalent function diffDates for usages in other modules
-//module.exports = DatesYMD; // default export for class
-module.exports= config; // named export for integrating to Date
+module.exports = DatesYMD; // default export for class
 module.exports.diffDates = diffDates; // named export for equivalent function
-//module.exports.config = config; // named export for integrating to Date