docs: move MUI to supported list (#52584)

fixes #52575

---------

Co-authored-by: Lee Robinson <me@leerob.io>
Co-authored-by: Alexandre Fauquette <45398769+alexfauquette@users.noreply.github.com>
Co-authored-by: Steven <steven@ceriously.com>
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

docs/02-app/01-building-your-application/04-styling/03-css-in-js.mdx

@@ -14,6 +14,7 @@ description: Use CSS-in-JS libraries with Next.js
 The following libraries are supported in Client Components in the `app` directory (alphabetical):
 
 - [`kuma-ui`](https://kuma-ui.com)
+- [`@mui/material`](https://mui.com/material-ui/guides/next-js-app-router/)
 - [`pandacss`](https://panda-css.com)
 - [`styled-jsx`](#styled-jsx)
 - [`styled-components`](#styled-components)
@@ -24,7 +25,6 @@ The following libraries are supported in Client Components in the `app` director
 The following are currently working on support:
 
 - [`emotion`](https://github.com/emotion-js/emotion/issues/2928)
-- [Material UI](https://github.com/mui/material-ui/issues/34905#issuecomment-1401306594)
 
 > **Good to know**: We're testing out different CSS-in-JS libraries and we'll be adding more examples for libraries that support React 18 features and/or the `app` directory.