Adding the possibility to add multiple ui components in the live code editor in the docs (#2381)

* working

* forgot docs folder

* modify according to comments

docs/docs/contributor/frontend/ui-components/display/checkmark.mdx

@@ -6,11 +6,13 @@ sidebar_position: 1
 import { SandpackEditor} from '@site/src/ui/SandpackEditor'
 
 <SandpackEditor
-  componentPath='@/ui/Checkmark/components/Checkmark'
+  availableComponentPaths={['@/ui/Checkmark/components/Checkmark', '@/ui/Button/components/Button']}
   componentCode={`import { Checkmark } from "@/ui/Checkmark/components/Checkmark";
-
+import { Button } from "@/ui/Button/components/Button";
 export const MyComponent = () => {
- return <Checkmark />;
+ return <><Checkmark /><Button title="New task"
+          variant={'secondary'}
+          onClick={() => console.log('click')}/></>
 }
 `} 
 />