Update Echo README

Examples/Echo/README.md

@@ -6,12 +6,13 @@ Streaming, Client Streaming, and Bidirectional Streaming).
 It includes Swift and Go implementations to verify 
 interoperability.
 
-The [Swift](Swift) directory contains a Mac app and a command-line tool
+The [Xcode](Xcode) directory contains a Mac app and 
+[SwiftPM](SwiftPM) contains a command-line tool
 that can be built with the Swift Package Manager. Both contain
 a Swift client and server, and both are hard-coded to use port
 8081 for insecure connections and port 8443 for secure connections.
 
-The [Go](Go) directory contains a Go client and server. The server
+The [Go](Go) directory contains a Go client and server. The Go server
 listens on port 8080 and the Go client connects to this by
 default but can be pointed at other servers using the "-a" 
 command-line option.