➕(react) add material icons

We need some icons to implement the Pagination and the DataGrid.

packages/react/src/docs/installation.stories.mdx

@@ -54,6 +54,7 @@ Then, add these lines at the top of your main stylesheet file:
   format={false}
   code={`
 @import "@openfun/cunningham-react/fonts"; // Imports default fonts ( Roboto ). You can also import fonts by yourself.
+@import "@openfun/cunningham-react/icons"; // Imports icons ( Material Icons ).
 @import "@openfun/cunningham-react/style"; // Imports the default theme.
 @import "cunningham-tokens"; // Imports the file you just generated.
   `}