feat: support multiple extensions for routes file

.changeset/cold-icons-lick.md

@@ -0,0 +1,5 @@
+---
+'rsbuild-plugin-react-router': patch
+---
+
+search for routes file with any extention

.changeset/social-flowers-itch.md

@@ -0,0 +1,5 @@
+---
+'rsbuild-plugin-react-router': patch
+---
+
+support multiple extentions for routes file, like js,ts,jsx etc

src/index.ts

@@ -97,16 +97,16 @@ export const pluginReactRouter = (
         return {} as Config;
       });
 
-    const routesPath = resolve(appDirectory, 'routes.ts');
+    const routesPath = findEntryFile(resolve(appDirectory, 'routes'));
 
     // Then read the routes
     const routeConfig = await jiti
       .import<RouteConfigEntry[]>(routesPath, {
         default: true,
       })
       .catch(error => {
-        console.error('Failed to load routes.ts:', error);
-        console.error('No routes.ts found in app directory.');
+        console.error('Failed to load routes file:', error);
+        console.error('No routes file found in app directory.');
         return [] as RouteConfigEntry[];
       });