README: Update repository contents
This repository contains the source code for the network components of The Graph.
Right now, this includes:
-1. A common library used by all nodes, called `thegraph`.
-2. A local-only The Graph node, called `thegraph-local-node`.
+1. `thegraph-local-node`: A local-only The Graph node.
+2. `thegraph`: A library providing traits for system components and types for common data.
+3. `thegraph-core`: A library providing implementations for core components, used by all nodes.
+4. `thegraph-hyper`: A library providing an implementation of the GraphQL server component
+ based on Hyper.
+5. `thegraph-mock`: A library providing mock implementations for all system components.
## Prerequisites
