Fix godoc for http.RequestDecoder()
@@ -55,6 +55,7 @@ type (
// * application/json using package encoding/json
// * application/xml using package encoding/xml
// * application/gob using package encoding/gob
+// * text/html and text/plain for strings
//
// RequestDecoder defaults to the JSON decoder if the request "Content-Type"
// header does not match any of the supported mime type or is missing
