refactor:[kakao-tech-campus-2nd-step3#84]- refact ProductApi

APi 반환 타입 변경

src/main/java/com/helpmeCookies/product/controller/docs/ProductApiDocs.java

@@ -21,5 +21,5 @@ public ResponseEntity<ApiResponse<Paging>> getProductsByPage(
         @RequestParam(name = "size", required = false, defaultValue = "20") int size,
         @RequestParam("page") int page,
         @RequestParam("sort") ProductSort productSort
-    )
+    );
 }