Add Category attribute for types grouping in editor dialogs

Source/Engine/Scripting/Attributes/Editor/CategoryAttribute.cs

@@ -0,0 +1,27 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+using System;
+
+namespace FlaxEngine
+{
+    /// <summary>
+    /// Describes the category name for a type.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface)]
+    public sealed class CategoryAttribute : Attribute
+    {
+        /// <summary>
+        /// The category name.
+        /// </summary>
+        public string Name;
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="CategoryAttribute"/> class.
+        /// </summary>
+        /// <param name="name">The category name.</param>
+        public CategoryAttribute(string name)
+        {
+            Name = name;
+        }
+    }
+}