docs: add simplebar (#1360)

Author: jdegand

README.md

@@ -1814,6 +1814,7 @@ to simplify usage and allow quick customization.
 * [ng-inf-scroll](https://github.com/lukonik/ng-inf-scroll) - A lightweight library for adding infinite scrolling to Angular apps.
 * [ng-mat-select-infinite-scroll](https://github.com/HaidarZ/ng-mat-select-infinite-scroll) - Infinite Scroll directive for Angular Material select component.
 * [horizontal-scroller](https://github.com/miminerd/horizontal-scroller) - Infinite horizontal scroller for Angular apps using Tailwind.
+* [simplebar](https://github.com/Grsmto/simplebar) - Custom scrollbars vanilla JavaScript library with native scroll, done simple, lightweight, easy to use and cross-browser.
 
 #### State Management