Added quiz features

app/Models/QuizSubject.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class QuizSubject extends Model
+{
+    use HasFactory;
+
+    protected $fillable = [
+        'title',
+        'slug',
+    ];
+
+    public function questions()
+    {
+        return $this->hasMany(Question::class, 'subject_id');
+    }
+}