Create QUESTIONS.md

doc/QUESTIONS.md

+## WeChat Not Installed on iOS?
+if you have installed WeChat on your iPhone but you still catch an exception that "wechat not installed",just add the following
+code to your *info.plist*:
+```xml
+<key>LSApplicationQueriesSchemes</key>
+<array>
+<string>weixin</string>
+</array>
+<key>NSAppTransportSecurity</key>
+<dict>
+<key>NSAllowsArbitraryLoads</key>
+<true/>
+</dict>
+```