Metadata - Tags の多対多リレーション追加

app/Metadata.php

@@ -14,4 +14,9 @@ class Metadata extends Model
     protected $visible = ['url', 'title', 'description', 'image', 'expires_at'];
 
     protected $dates = ['created_at', 'updated_at', 'expires_at'];
+
+    public function tags()
+    {
+        return $this->belongsToMany(Tag::class)->withTimestamps();
+    }
 }