lots of improvements

app/Models/ForumCategory.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class ForumCategory extends Model
+{
+    protected $fillable = [
+        'name',
+        'slug',
+        'description',
+        'order',
+    ];
+
+    /**
+     * Get the threads for the category.
+     */
+    public function threads()
+    {
+        return $this->hasMany(ForumThread::class, 'category_id');
+    }
+
+    /**
+     * Get the route key for the model.
+     *
+     * @return string
+     */
+    public function getRouteKeyName()
+    {
+        return 'slug';
+    }
+}