docs: improve README.md

Author: Liadshiran

packages/toolkit/README.md

@@ -57,13 +57,14 @@ Redux Toolkit also includes a powerful data fetching and caching capability that
 
 Redux Toolkit includes these APIs:
 
-- `configureStore()`: wraps `createStore` to provide simplified configuration options and good defaults. It can automatically combine your slice reducers, adds whatever Redux middleware you supply, includes `redux-thunk` by default, and enables use of the Redux DevTools Extension.
-- `createReducer()`: that lets you supply a lookup table of action types to case reducer functions, rather than writing switch statements. In addition, it automatically uses the [`immer` library](https://github.com/mweststrate/immer) to let you write simpler immutable updates with normal mutative code, like `state.todos[3].completed = true`.
+- `configureStore()`: wraps `createStore` to provide simplified configuration options and good defaults. It can automatically combine your slice reducers, add whatever Redux middleware you supply, it includes `redux-thunk` by default, and enables use of the Redux DevTools Extension.
+- `createReducer()`: lets you supply a lookup table of action types to case reducer functions, rather than writing switch statements. In addition, it automatically uses the [`immer` library](https://github.com/mweststrate/immer) to let you write simpler immutable updates with normal mutative code, like `state.todos[3].completed = true`.
 - `createAction()`: generates an action creator function for the given action type string. The function itself has `toString()` defined, so that it can be used in place of the type constant.
-- `createSlice()`: accepts an object of reducer functions, a slice name, and an initial state value, and automatically generates a slice reducer with corresponding action creators and action types.
-- `createAsyncThunk`: accepts an action type string and a function that returns a promise, and generates a thunk that dispatches `pending/resolved/rejected` action types based on that promise
-- `createEntityAdapter`: generates a set of reusable reducers and selectors to manage normalized data in the store
-- The `createSelector` utility from the [Reselect](https://github.com/reduxjs/reselect) library, re-exported for ease of use.
+- `createSlice()`: combines  `createReducer()` + `createAction()`. Accepts an object of reducer functions, a slice name, and an initial state value, and automatically generates a slice reducer with corresponding action creators and action types.
+- `createListenerMiddleware()`: lets you define "listener" entries that contain an "effect" callback with additional logic, and a way to specify when that callback should run based on dispatched actions or state changes. A lightweight alternative to Redux async middleware like sagas and observables. 
+- `createAsyncThunk()`: accepts an action type string and a function that returns a promise, and generates a thunk that dispatches `pending/resolved/rejected` action types based on that promise
+- `createEntityAdapter()`: generates a set of reusable reducers and selectors to manage normalized data in the store
+- The `createSelector()` utility from the [Reselect](https://github.com/reduxjs/reselect) library, re-exported for ease of use.
 
 ## RTK Query