Update README.

Author: devxoul

README.md

@@ -1,10 +1,52 @@
-SwipeBack
-=========
+# SwipeBack
 
 Re-enable iOS7 swipe-to-back with custom back button.
 
 
-Just import it.
----------------
+## Background
 
-`#import <SwipeBack/SwipeBack.h>`
+1. With setting custom back button via `leftBarButtonItem`, default swipe-to-back gesture is disabled.
+2. Assigning `interactivePopGestureRecognizer` as `UINavigationController` (a common solution) can cause unexpected errors:
+
+    > - nested pop animation can result in corrupted navigation bar
+    > - Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
+
+3. Put custom code everywhere around `UINavigationController` is too annoying.
+
+
+## The Answer is SwipeBack
+
+1. **Not annoying**  
+You don't need to code.
+
+2. **iOS7 native behavior**  
+Not a foolishly-customized gesture recognizer.
+
+3. **Safe**  
+No error anymore.
+
+
+## Use SwipeBack
+
+### CocoaPods
+
+Just add a line below into your `Podfile`. You don't need to write any code. CocoaPods automatically import SwipeBack globally.
+
+```
+pod 'SwipeBack'
+```
+
+### Without CocoaPods (Why not use?)
+
+Import SwipeBack at your `.pch` file.
+
+```
+#import "SwipeBack.h"
+```
+
+It's done.
+
+
+## How does it work
+
+See [`UINavigationController+SwipeBack.m`](https://github.com/devxoul/SwipeBack/blob/master/SwipeBack/UINavigationController%2BSwipeBack.m) and [`UIViewController+SwipeBack.m`](https://github.com/devxoul/SwipeBack/blob/master/SwipeBack/UIViewController%2BSwipeBack.m). Want to know more about method swizzling, visit [here](http://nshipster.com/method-swizzling/).

SwipeBack.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "SwipeBack"
-  s.version      = "0.1.0"
+  s.version      = "1.0.0"
   s.summary      = "SwipeBack"
   s.homepage     = "http://github.com/devxoul/SwipeBack"
   s.license      = { :type => 'MIT', :file => 'LICENSE' }