add element endpoint

backend/routes/api.php

@@ -1,6 +1,7 @@
 <?php
 
 use App\Controllers\AuthController;
+use App\Controllers\ElementController;
 use App\Controllers\SetController;
 use App\Http\Middleware\AuthMiddleware;
 use Illuminate\Support\Facades\Route;
@@ -10,3 +11,4 @@ Route::post('/logout', [AuthController::class, 'logout']);
 Route::get('/me', [AuthController::class, 'me'])
     ->middleware(AuthMiddleware::class);
 Route::get('/sets', [SetController::class, 'index']);
+Route::get('/elements/{id}', [ElementController::class, 'show']);