Moved README to root

When the `OnTopic-MVC` project was part of the `OnTopic-Library` project, the root `README.md` file was for the entirety of the OnTopic library. Now that the `OnTopic.Web.Mvc` project has been broken out into its own repository, the `OnTopic.Web.Mvc/README.md` makes sense in the root of the project. (There are other projects besides the `OnTopic.Web.Mvc` project, but they're closely related, like the `Host` and `Tests` projets.)

Author: JeremyCaney

OnTopic.Web.Mvc/README.md renamed to README.md

@@ -1,5 +1,5 @@
 # `Ignia.Topics.Web.Mvc`
-The `Ignia.Topics.Web.Mvc` assembly provides a default implementation for utilizing OnTopic with the ASP.NET MVC 5.x Framework.
+The `Ignia.Topics.Web.Mvc` assembly provides an implementation of OnTopic for use with the ASP.NET MVC 5.x Framework.
 
 ### Contents
 - [Components](#components)