Updated verseion numbers in CDN

Author: cferdinandi

README.md

@@ -43,13 +43,13 @@ You can also use the [jsDelivr CDN](https://cdn.jsdelivr.net/gh/cferdinandi/smoo
 <script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll/dist/smooth-scroll.polyfills.min.js"></script>
 
 <!-- Get minor updates and patch fixes within a major version -->
-<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@14/dist/smooth-scroll.polyfills.min.js"></script>
+<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@15/dist/smooth-scroll.polyfills.min.js"></script>
 
 <!-- Get patch fixes within a minor version -->
-<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@14.0/dist/smooth-scroll.polyfills.min.js"></script>
+<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@15.0/dist/smooth-scroll.polyfills.min.js"></script>
 
 <!-- Get a specific version -->
-<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@14.0.0/dist/smooth-scroll.polyfills.min.js"></script>
+<script src="https://cdn.jsdelivr.net/gh/cferdinandi/smooth-scroll@15.0.0/dist/smooth-scroll.polyfills.min.js"></script>
 ```
 
 **NPM**