fix: Constants export in index.js (#285)

* fix: add Constants export in index.js
* fix: add missing constants export in index.d.ts


Co-authored-by: Pedro S. Lopez <pedroslopez@me.com>

index.d.ts

@@ -300,6 +300,12 @@ declare namespace WAWebJS {
 
   }
 
+  /** whatsapp web url */
+  export const WhatsWebURL: string
+  
+  /** default client options */
+  export const DefaultOptions: ClientOptions
+
   /** Chat types */
   export enum ChatTypes {
     SOLO = 'solo',