doc: fix install command and use the right markdown flag

ericmdantas · ericmdantas · commit 54ae6dbd29ce · 2016-09-27T07:13:59.000-03:00
diff --git a/README.md b/README.md
@@ -27,10 +27,8 @@ Key & Unique Features
 Installation
 -----------
 
-Use go get 
-
-```go
-go -u get github.com/go-playground/lars
+```shell
+go get -u github.com/go-playground/lars
 ```
 
 Usage
