Update README.md

Author: Tkc

example/README.md

@@ -2,11 +2,11 @@
 
 ## Install
 ```
-go install github.com/tkc/go-json-server
+$ go get -u github.com/tkc/go-json-server
 ```
 
 ## Run
 
 ```
-go-json-server
+$ go-json-server
 ```