README updates.

QuickProto/README.md

@@ -0,0 +1,8 @@
+
+QuickProto is a simple library for reading and writing Protocol Buffers
+with no code generation. It is intended for use in testing, temporary 
+scaffolding, and any situations where protocol buffer definitions are not
+known at build time.
+
+QuickProto requires a binary FileDescriptorSet representation of the protos
+to be read. This can be generated by the protoc compiler using the -o option.

README.md

@@ -28,3 +28,11 @@ the instructions in the [Packages](Packages) directory.
 by the addition of Grand Central Dispatch APIs for streaming
 API support; they will be fixed when threading-related 
 incompatibilities between Linux and Darwin are resolved).
+
+## Can't find something?
+
+It was harder to get the Swift package manager to deal with 
+code in outside directories than to point Xcode at them, so
+you'll find the code for gRPC, CgRPC, and QuickProto in the
+Sources directory associated with each package.
+