Change the messaging of comparison to other libraries / frameworks

The docs seem to take many shots at React.js. While it's great that Binding.Scala is offering improvements over React, this creates an adversarial impression. Also, React isn't the only player out there in JS-land, nor in ScalaJS-land.

Instead, it'd be nice to have a Comparisons to Other Libraries section. It could mention React, as well as the ScalaJS React port, Vue.js, Cycle.js, as well as some other ScalaJS libs such as Outwatch and Udash.

Just my 2c on the messaging.