fix: fixed an overlapping issue when components were using z indexes by overwriting said z-index. for the showcase. the stacking order inside of the component should stay the same

Author: FinumSamBrun

src/RocketJsDemo.js

@@ -250,6 +250,7 @@ export class RocketJsDemo extends LitElement {
         background-color: #eee;
         width: 100%;
         overflow: hidden;
+        z-index: 0;
       }
 
       #resize {