Add documentation about new API

Author: zalmoxisus

README.md

@@ -58,6 +58,8 @@
 
  - [FAQ](docs/FAQ.md)
  - [API](docs/API.md)
+  - [Apply as Redux store enhancer](docs/API.md#windowdevtoolsextensionconfig)
+  - [Create Redux store right in the extension](docs/API.md#windowdevtoolsextensionreducer-initialstate-config)
 
 ## Videos
 

docs/API.md

@@ -0,0 +1,53 @@
+# API Reference
+
+`window.devToolsExtension` function can be used in 2 ways:
+ 1. [Apply as Redux store enhancer](#windowdevtoolsextensionconfig)
+ 2. [Create Redux store right in the extension](#windowdevtoolsextensionreducer-initialstate-config).
+
+
+### `window.devToolsExtension([config])`
+- [`config`] *(object)*: options
+  - **name** (*string*) - the instance name to be showed on the monitor page. Default value is `document.title`.
+  - **deserializeState(state): transformedState** (*function*) - optional transformation of state deserialized from debug session (useful if state is not plain object. Example: immutable-js state)
+    - state, transformedState - Redux state objects.
+      Example of usage:
+      
+      ```js
+      const store = createStore(rootReducer, window.devToolsExtension && window.devToolsExtension({
+        deserializeState: (state) => ({
+          todos: {
+            ...state.todos,
+            todoList: Immutable.fromJS(state.todos.todoList)
+          }
+        })
+      }));
+      ```
+  - **deserializeAction(action): transformedAction** (*function*) - optional transformation of actions deserialized from debug session (useful if actions are not plain object. Example: immutable-js action payload)
+    - action, transformedAction - Redux action objects
+  - **actionsBlacklist** (*array*) - actions to be hidden in DevTools. Overwrites corresponding global setting in the options page.
+  - **actionsWhitelist** (*array*) - all other actions will be hidden in DevTools. Overwrites corresponding global setting in the options page.
+  - **actionsFilter** (*function*) - function which takes `action` object and id number as arguments, and should return `action` object back. See the example bellow.
+  - **statesFilter** (*function*) - function which takes `state` object and index as arguments, and should return `state` object back.
+      Example of usage:
+      
+      ```js
+      const actionsFilter = (action) => (
+        action.type === 'FILE_DOWNLOAD_SUCCESS' && action.data ?
+        { ...action, data: '<<LONG_BLOB>>' } : action
+      );
+      const store = createStore(rootReducer, window.devToolsExtension && window.devToolsExtension({
+        actionsFilter,
+        statesFilter: (state) => state.data ? { ...state, data: '<<LONG_BLOB>>' } : state)
+      }));
+      ```
+
+### `window.devToolsExtension(reducer, [preloadedState, config])`
+> Note: This is not intended to replace Redux' `createStore`. Use this approach only when you want to inspect changes outside of Redux or when not using Redux inside your application.
+
+1. `reducer` *(Function)*: A [reducing function](https://github.com/reactjs/redux/blob/master/docs/Glossary.md#reducer) that returns the next [state tree](../Glossary.md#state), given the current state tree and an [action](https://github.com/reactjs/redux/blob/master/docs/Glossary.md#action) to handle.
+
+2. [`preloadedState`] *(any)*: The initial state. You may optionally specify it to hydrate the state from the server in universal apps, or to restore a previously serialized user session. If you produced `reducer` with [`combineReducers`](combineReducers.md), this must be a plain object with the same shape as the keys passed to it. Otherwise, you are free to pass anything that your `reducer` can understand.
+
+3. [`config`] *(Object)*: options. See [above](#windowdevtoolsextensionconfig) for details.
+
+[Example of usage](https://github.com/zalmoxisus/redux-devtools-extension/commit/1810d2c1f0e8be1daf8f2d8f7bbeb4f8c528d90b).