Update plugin.md

Fix small typo

Author: mustevenplay

docs/concept/plugin.md

@@ -90,7 +90,7 @@ Config type will be inferred into `use`, generating auto completion and type str
 
 ## Plugin deduplication
 
-By default, Elysia will register any plugin and handle type definitions which when using multiple times will results in a multiple duplication of setting value or routes.
+By default, Elysia will register any plugin and handle type definitions which when using multiple times will result in a multiple duplication of setting value or routes.
 
 This can be fixed by providing name and optional seeds to help Elysia identify instance duplication: