chore: add known issues section to readme (#298)

Author: troZee

README.md

@@ -175,6 +175,16 @@ To fix formatting errors, run the following:
 yarn lint --fix
 ```
 
+## Known Issues
+
+- `flex:1` does not work for child views, please use `width:”100%”, height:”100%” ` [instead](https://github.com/react-native-community/react-native-viewpager/issues/186#issuecomment-675320732)
+
+- [iOS]: In case of `UIViewControllerHierarchyInconsistency` error, please use below fix:
+ 
+```
+requestAnimationFrame(() => refViewPager.current?.setPage(index));
+```
+
 ## Preview
 
 ### Android