[fix] image path

Author: i4004

README.md

@@ -61,7 +61,7 @@ public class GetController : Simplify.Web.Controller
 
 Below is the example of Swagger generated by `Simplify.Web.Swagger`:
 
-![Simplify](https://raw.githubusercontent.com/SimplifyNet/Simplify.Web.Swagger/master/images/screenshots/generated-swagger-sample.png.png)
+![Simplify](https://raw.githubusercontent.com/SimplifyNet/Simplify.Web.Swagger/master/images/screenshots/generated-swagger-sample.png)
 
 ## Contributing