clarify httpserver.Middleware

Converting-Add-ons-to-Plugins.md

@@ -87,7 +87,7 @@ To test that the middleware was set up properly, you'll need to get the config i
 
 ```go
 cfg := httpserver.GetConfig("")
-mids := cfg.Middleware() // []Middleware
+mids := cfg.Middleware() // []httpserver.Middleware
 ```
 
 From there, you'll usually want the last middleware in the list, `mids[len(mids)-1]`. If you're not in a loop you can just assume `mids[0]`. Of course, if you didn't add any middleware, you can omit these checks.