Format directory/file references (#5184)

examples/route_guide/README.md

@@ -4,11 +4,11 @@ perform unary, client streaming, server streaming and full duplex RPCs.
 
 Please refer to [gRPC Basics: Go](https://grpc.io/docs/tutorials/basic/go.html) for more information.
 
-See the definition of the route guide service in routeguide/route_guide.proto.
+See the definition of the route guide service in `routeguide/route_guide.proto`.
 
 # Run the sample code
-To compile and run the server, assuming you are in the root of the route_guide
-folder, i.e., .../examples/route_guide/, simply:
+To compile and run the server, assuming you are in the root of the `route_guide`
+folder, i.e., `.../examples/route_guide/`, simply:
 
 ```sh
 $ go run server/server.go