docs: add explicit import to TypeScript augmentation example (#14957)

* docs: add explicit import to TypeScript augmentation example

In the "Quick Start (Data Mode)" section, the TypeScript module augmentation example for Future can cause errors if the user's .d.ts file is treated as a global script rather than a module.

Without a top-level import or export, TypeScript interprets declare module "react-router" as a full ambient declaration, which shadows/overwrites the actual library types instead of augmenting them. Adding import "react-router"; ensures the file is treated as a module and triggers Module Augmentation correctly.

* Add NandkishorJadoun to contributors list

Author: NandkishorJadoun

contributors.yml

@@ -486,3 +486,4 @@
 - zeromask1337
 - zheng-chuang
 - zxTomw
+- NandkishorJadoun

docs/how-to/middleware.md

@@ -136,6 +136,9 @@ In order to properly type your `context` param in your `loader`/`action`/`middle
 
 ```ts
 // src/react-router.d.ts
+
+import "react-router"
+
 declare module "react-router" {
   interface Future {
     v8_middleware: true;