Tweak immutable middleware docs typos

Author: markerikson

docs/api/getDefaultMiddleware.md

@@ -58,9 +58,7 @@ provide runtime checks for two common issues:
 - [`immutable-state-invariant`](./otherExports.md#createimmutablestateinvariantmiddleware): deeply compares
   state values for mutations. It can detect mutations in reducers during a dispatch, and also mutations that occur between
   dispatches (such as in a component or a selector). When a mutation is detected, it will throw an error and indicate the key
-  path for where the mutated value was detected in the state tree.
-
-  Forked from [`redux-immutable-state-invariant`](https://github.com/leoasis/redux-immutable-state-invariant)
+  path for where the mutated value was detected in the state tree. (Forked from [`redux-immutable-state-invariant`](https://github.com/leoasis/redux-immutable-state-invariant).)
 
 - [`serializable-state-invariant-middleware`](./otherExports.md#createserializablestateinvariantmiddleware): a custom middleware created specifically for use in Redux Toolkit. Similar in
   concept to `immutable-state-invariant`, but deeply checks your state tree and your actions for non-serializable values

docs/api/otherExports.md

@@ -11,7 +11,7 @@ Redux Toolkit exports some of its internal utilities, and re-exports additional
 
 ## Internal Exports
 
-### `createImmutalStateInvariantMiddleware`
+### `createImmutableStateInvariantMiddleware`
 
 Creates an instance of the `immutable-state-invariant` middleware described in [`getDefaultMiddleware`](./getDefaultMiddleware.md).