docs: updating drei url (#571)

Author: abernier

readme.md

@@ -49,7 +49,7 @@ A camera control for three.js, similar to THREE.OrbitControls yet supports smoot
 - [WebWorker (OffscreenCanvas)](https://yomotsu.github.io/camera-controls/examples/worker.html)
 - [outside of iframe dragging](https://yomotsu.github.io/camera-controls/examples/iframe.html)
 - [in react-three-fiber (simplest)](https://codesandbox.io/s/react-three-fiber-camera-controls-4jjor?file=/src/App.tsx)
-- [in react-three-fiber (drei official)](https://codesandbox.io/s/sew669) (see [doc](https://github.com/pmndrs/drei#cameracontrols))
+- [in react-three-fiber (drei official)](https://codesandbox.io/s/sew669) (see [doc](https://drei.docs.pmnd.rs/controls/camera-controls))
 
 ## Usage