♻️(demo) demonstrate token references

Demonstrate the use of token references by editing the greyscale
color which is used by lots of components.

apps/demo/src/App.tsx

@@ -1,9 +1,10 @@
 import {
   Button,
-  usePagination,
-  Pagination,
   CunninghamProvider,
+  Pagination,
   SUPPORTED_LOCALES,
+  Switch,
+  usePagination,
 } from "@openfun/cunningham-react";
 import React, { useState } from "react";
 import { tokens } from "./cunningham-tokens";
@@ -26,6 +27,7 @@ export const App = () => {
             </option>
           ))}
         </select>
+        <Switch defaultChecked={true} />
         <Button>World best button.</Button>
         <h3>Primary-500 color is {tokens.theme.colors["primary-500"]}</h3>
         <Pagination {...pagination} />