update README.md

Author: Cliffus

README.md

@@ -118,6 +118,14 @@ expandableTextView.setOnExpandListener(new ExpandableTextView.OnExpandListener()
 });
 ```
 
+Roadmap
+=======
+
+* take into account TextView padding and margin
+* optional fading edge at the bottom of the TextView
+* support for Interpolators
+* update demo project with more examples
+
 License
 =======