update docs

Author: EskiMojo14

docs/api/createSlice.mdx

@@ -57,14 +57,16 @@ function createSlice({
     name: string,
     // The initial state for the reducer
     initialState: State,
-    // An object of "case reducers". Key names will be used to generate actions.
-    reducers: Record<string, ReducerFunction | ReducerAndPrepareObject>,
+    // An object of "case reducers", or a callback that returns an object. Key names will be used to generate actions.
+    reducers: Record<string, ReducerFunction | ReducerAndPrepareObject> | ((create: ReducerCreators<State>) => Record<string, ReducerDefinition>),
     // A "builder callback" function used to add more reducers
     extraReducers?: (builder: ActionReducerMapBuilder<State>) => void,
     // A preference for the slice reducer's location, used by `combineSlices` and `slice.selectors`. Defaults to `name`.
     reducerPath?: string,
     // An object of selectors, which receive the slice's state as their first parameter.
     selectors?: Record<string, (sliceState: State, ...args: any[]) => any>,
+    // An object of custom slice creators, used by the reducer callback.
+    creators?: Record<string, ReducerCreator>
 })
 ```
 
@@ -456,6 +458,14 @@ const counterSlice = createSlice({
 
 :::
 
+### `creators`
+
+While typically [custom creators](/usage/custom-slice-creators) will be provided on a per-app basis (see [`buildCreateSlice`](#buildcreateslice)), this field allows for custom slice creators to be passed in per slice.
+
+This is particularly useful when using a custom creator that is specific to a single slice.
+
+An error will be thrown if there is a naming conflict between an app-wide custom creator and a slice-specific custom creator.
+
 ## Return Value
 
 `createSlice` will return an object that looks like:

docs/usage/custom-slice-creators.mdx

@@ -48,6 +48,12 @@ const { undo, redo, reset, updateTitle, togglePinned } =
 
 In order to use slice creators, `reducers` becomes a callback, which receives a `create` object. This `create` object contains a couple of [inbuilt creators](#rtk-creators), along with any creators passed to [`buildCreateSlice`](../api/createSlice#buildcreateslice).
 
+:::note
+
+Creators can also be [passed per slice](/api/createSlice#creators), but most creators will be useful in more than one slice - so it's recommended to pass them to `buildCreateSlice` instead.
+
+:::
+
 ```ts title="Creator callback for reducers"
 import { buildCreateSlice, asyncThunkCreator, nanoid } from '@reduxjs/toolkit'
 
@@ -166,7 +172,7 @@ The [creator definition](#creator-definitions) for `create.preparedReducer` is e
 
 These creators are not included in the default `create` object, but can be added by passing them to [`buildCreateSlice`](../api/createSlice#buildcreateslice).
 
-The name the creator is available under is based on the key used when calling `buildCreateSlice`. For example, to use `create.asyncThunk`:
+The name the creator is available under is based on the key used when calling `buildCreateSlice` (or [`createSlice`](/api/createSlice#creators)). For example, to use `create.asyncThunk`:
 
 ```ts
 import { buildCreateSlice, asyncThunkCreator } from '@reduxjs/toolkit'
@@ -464,7 +470,7 @@ Typically a creator will return a [single reducer definition](#single-definition
 
 A creator definition contains the actual runtime logic for that creator. It's an object with a `type` property, a `create` method, and an optional `handle` method.
 
-It's passed to [`buildCreateSlice`](../api/createSlice#buildcreateslice) as part of the `creators` object, and the name used when calling `buildCreateSlice` will be the key the creator is nested under in the `create` object.
+It's passed to [`buildCreateSlice`](../api/createSlice#buildcreateslice) (or [`createSlice`](/api/createSlice#creators)) as part of the `creators` object, and the name used when calling `buildCreateSlice` will be the key the creator is nested under in the `create` object.
 
 ```ts no-transpile
 import { buildCreateSlice } from '@reduxjs/toolkit'