Merge pull request gin-gonic#993 from easonlin404/docs

Add SecureJSON doc

README.md

@@ -559,6 +559,29 @@ func main() {
 }
 ```
 
+#### SecureJSON
+
+Using SecureJSON to prevent json hijacking. Default prepends `"while(1),"` to response body if the given struct is array values.
+
+```go
+func main() {
+	r := gin.Default()
+
+	// You can also use your own secure json prefix
+	// r.SecureJsonPrefix(")]}',\n")
+
+	r.GET("/someJSON", func(c *gin.Context) {
+		names := []string{"lena", "austin", "foo"}
+
+		// Will output  :   while(1);["lena","austin","foo"]
+		c.SecureJSON(http.StatusOK, names)
+	})
+
+	// Listen and serve on 0.0.0.0:8080
+	r.Run(":8080")
+}
+```  
+
 ### Serving static files
 
 ```go