Fixed #17003 | Documentation: Theming, Presets wrong link

apps/showcase/doc/theming/presetsdoc.ts

@@ -6,8 +6,8 @@ import { Component } from '@angular/core';
         <app-docsectiontext>
             <p>
                 Aura, Material, Lara and Nora are the available built-in options, created to demonstrate the power of the design-agnostic theming. Aura is PrimeTek's own vision, Material follows Google Material Design v2, Lara is based on Bootstrap
-                and Nora is inspired by enterprise applications. Visit the <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/@layer" target="_blank" rel="noopener noreferrer">source code</a> to learn more about the structure of presets. You
-                may use them out of the box with modifications or utilize them as reference in case you need to build your own presets from scratch.
+                and Nora is inspired by enterprise applications. Visit the <a href="https://github.com/primefaces/primeng/tree/master/packages/themes/src/presets" target="_blank" rel="noopener noreferrer">source code</a> to learn more about the
+                structure of presets. You may use them out of the box with modifications or utilize them as reference in case you need to build your own presets from scratch.
             </p>
         </app-docsectiontext>
     `