Merge pull request #525 from alibaba/doc-feature-update-ios-integrate

* [doc] update integrate doc for iOS

doc/advanced/integrate-to-ios.md

@@ -18,10 +18,16 @@ Copy the whole folder `/ios/sdk` to your project directory.
 
 Before adding the dependencies, please confirm that the project directory already exists the Podfile. If not, create a new one. Then, edit this file, adding some necessary dependecis for the target.
 
-```
+``` 
+target 'YourTarget' do
 	platform :ios, '7.0'
 	pod 'WeexSDK', :path=>'./sdk/'
+end
 ```
+You can get your `YourTarget` below
+
+![img](http://img4.tbcdn.cn/L1/461/1/4d9f4d6a8441b44e4816c7778627824fb72c58de)
+
 Run pod install in current directory, for a while, .xcworkspace will be created.  At this point, the dependencies have been established.
 
 #### 3. Init Weex Environment