docs: remove dead link from readme (pmndrs#1302)

readme.md

@@ -370,7 +370,7 @@ const dispatch = useGrumpyStore((state) => state.dispatch)
 dispatch({ type: types.increase, by: 2 })
 ```
 
-Or, just use our redux-middleware. It wires up your main-reducer, sets initial state, and adds a dispatch function to the state itself and the vanilla api. Try [this](https://codesandbox.io/s/amazing-kepler-swxol) example.
+Or, just use our redux-middleware. It wires up your main-reducer, sets initial state, and adds a dispatch function to the state itself and the vanilla api.
 
 ```jsx
 import { redux } from 'zustand/middleware'