Minor edits to Echo/README.md

Examples/Echo/README.md

@@ -2,16 +2,17 @@
 
 This directory contains a simple echo server and client
 that demonstrates all four gRPC API styles (Unary, Server 
-Streaming, Client Streaming, and Bidirectional Streaming) 
-and to verify interoperability of Swift and Go gRPC clients
-and servers.
+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
+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
-listens on localhost:8080 and the client connects to this by
+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.
 
-The [Swift](Swift) directory contains a Mac app and a command-line tool
-that can be built with the Swift Package Manager. Both contain
-a Swift client and server. 
-