Updte literal example to be a bit better

Author: NickCraver

Readme.md

@@ -202,7 +202,7 @@ Literal replacements
 Dapper supports literal replacements for bool and numeric types.
 
 ```csharp
-connection.Query("select * from User where UserId = {=Id}", new {Id = 1}));
+connection.Query("select * from User where UserTypeId = {=Admin}", new { UserTypeId.Admin }));
 ```
 
 The literal replacement is not sent as a parameter; this allows better plans and filtered index usage but should usually be used sparingly and after testing. This feature is particularly useful when the value being injected