docs: update README

Author: ameerthehacker

.idea/.gitignore

@@ -25,6 +25,13 @@ Lazyload your Components, Images or anything matters the performance.
 ## Installation
 
 > 2.0.0 is finally out, read [Upgrade Guide](https://github.com/twobin/react-lazyload/wiki/Upgrade-Guide), it's almost painless to upgrade!
+> 3.0.0 fixes the findDomNode warning through usage of React ref, and the following are the changes you need to be aware of
+
+* Now we have an extra div wrapping the lazy loaded component for the React ref to work 
+* We can understand that it is an extra DOM node, and we are working to optimize that if possible
+* It might break your UI or snapshot tests based on your usage
+* To customize the styling to the extra div please refer [here](###classNamePrefix)
+* Found any other problem, please feel free to leave a comment over [here](https://github.com/twobin/react-lazyload/issues/310)
 
 ```
 $ npm install --save react-lazyload

.idea/codeStyles/Project.xml

@@ -358,7 +358,7 @@ var LazyLoad = function (_Component) {
 
 
       return _react2.default.createElement(
-        'span',
+        'div',
         { className: classNamePrefix + '-wrapper', ref: this.setRef },
         this.visible ? children : placeholder ? placeholder : _react2.default.createElement('div', {
           style: { height: height },