Begin to update the readme to make it easier to remember which folder contains what.

Author: gareth-a-jones

README.md

@@ -1,2 +1,9 @@
 # Graph metadata used for generating client code files
-This repository contains scripts used to capture metadata from the Microsoft Graph service and the captured metadata. We use this metadata to generate code files for .Net, Java, TypeScript, PHP, and other languages.
+This repository contains scripts used to capture metadata from the Microsoft Graph service and the captured metadata.
+We use this metadata to generate code files for .Net, Java, TypeScript, PHP, and other languages.
+
+Here's a partial list of what you can find in some of the project's folders:
+
+`schema` - the files handed off, via a sync process, directly from the runtime engine of Microsoft Graph.
+
+`openapi` - OpenAPI format descriptions of the Microsoft Graph