Merge pull request #483 from richlander/rich-docsreadme

Convert document index into more GH-centric format

Author: richlander

Documentation/index.md renamed to Documentation/README.md

@@ -20,9 +20,9 @@ Want to chat with other members of the CoreCLR community?
 Historically, new devs to the CLR team would be encouraged to read the "Book of the Runtime" (BotR) before making substative changes to the product. We have released the meaningful BotR chapters and other documents, for the same goal with new contributors.
 
 - [Introduction to the Common Language Runtime](Documentation/intro-to-clr.md)
-- [Book of the Runtime](Documentation/index.md#book-of-the-runtime)
+- [Book of the Runtime](Documentation/README.md#book-of-the-runtime)
 - [CLR Coding Guide](Documentation/clr-code-guide.md)
-- [Documents Index](Documentation/index.md)
+- [Documents Index](Documentation)
 
 ## How to Engage, Contribute and Provide Feedback