Update readme file.

Author: ChebanovDD

README.md

@@ -8,6 +8,8 @@ This package is part of [UnityMvvmToolkit](https://github.com/LibraStack/UnityMv
 - [Folder Structure](#cactus-folder-structure)
 - [Installation](#gear-installation)
 - [How To Use](#joystick-how-to-use)
+  - [UxmlElement](#uxmlelement)
+  - [UxmlAttribute](#uxmlattribute)
 - [Contributing](#bookmark_tabs-contributing)
   - [Discussions](#discussions)
   - [Report a bug](#report-a-bug)
@@ -57,13 +59,15 @@ You can install **UnityUxmlGenerator** in one of the following ways:
 
   You can add `https://github.com/LibraStack/UnityUxmlGenerator.git?path=src/UnityUxmlGenerator.UnityPackage/Assets/Plugins/UnityUxmlGenerator` to the Package Manager.
 
-  If you want to set a target version, UnityUxmlGenerator uses the `v*.*.*` release tag, so you can specify a version like `#v0.0.1`. For example `https://github.com/LibraStack/UnityUxmlGenerator.git?path=src/UnityUxmlGenerator.UnityPackage/Assets/Plugins/UnityUxmlGenerator#v0.0.1-preview1`.
+  If you want to set a target version, UnityUxmlGenerator uses the `v*.*.*` release tag, so you can specify a version like `#v0.0.1`. For example `https://github.com/LibraStack/UnityUxmlGenerator.git?path=src/UnityUxmlGenerator.UnityPackage/Assets/Plugins/UnityUxmlGenerator#v0.0.1`.
 
 </details>
 
 ## :joystick: How To Use
 
-To create a custom control, just add the `[UxmlElement]` attribute to the custom control class definition. The custom control class must be declared as a partial class and be inherited from `VisualElement` or one of its derived classes.
+### UxmlElement
+
+To create a custom control, just add the `[UxmlElement]` attribute to the custom control class definition. The custom control class must be declared as a partial class and be inherited from `VisualElement` or one of its derived classes. By default, the custom control appears in the Library tab in UI Builder.
 
 You can use the `[UxmlAttribute]` attribute to declare that a property is associated with a `UXML` attribute.
 
@@ -85,52 +89,124 @@ public partial class CustomVisualElement : VisualElement
 <br />
 
 `CustomVisualElement.UxmlFactory.g.cs`
-  
+
 ```csharp
 partial class CustomVisualElement
 {
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("UnityUxmlGenerator", "1.0.0.0")]
-    public new class UxmlFactory : global::UnityEngine.UIElements.UxmlFactory<CustomVisualElement, UxmlTraits> 
+    [global::System.CodeDom.Compiler.GeneratedCode("UnityUxmlGenerator", "1.0.0.0")]
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+    public new class UxmlFactory : global::UnityEngine.UIElements.UxmlFactory<CustomVisualElement, UxmlTraits>
     {
     }
 }
 ```
 
 `CustomVisualElement.UxmlTraits.g.cs`
-  
+
 ```csharp
 partial class CustomVisualElement
 {
-    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("UnityUxmlGenerator", "1.0.0.0")]
+    [global::System.CodeDom.Compiler.GeneratedCode("UnityUxmlGenerator", "1.0.0.0")]
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
     public new class UxmlTraits : global::UnityEngine.UIElements.VisualElement.UxmlTraits
     {
-        [global::System.CodeDom.Compiler.GeneratedCodeAttribute("UnityUxmlGenerator", "1.0.0.0")]
-        private readonly global::UnityEngine.UIElements.UxmlStringAttributeDescription _customAttribute = new() 
-            { name = "custom-attribute", defaultValue = "" };
-
-        [global::System.CodeDom.Compiler.GeneratedCodeAttribute("UnityUxmlGenerator", "1.0.0.0")]
-        private readonly global::UnityEngine.UIElements.UxmlStringAttributeDescription _customAttributeWithDefaultValue = new() 
-            { name = "custom-attribute-with-default-value", defaultValue = "DefaultValue" };
-
-        [global::System.CodeDom.Compiler.GeneratedCodeAttribute("UnityUxmlGenerator", "1.0.0.0")]
+        [global::System.CodeDom.Compiler.GeneratedCode("UnityUxmlGenerator", "1.0.0.0")]
+        private readonly global::UnityEngine.UIElements.UxmlStringAttributeDescription _customAttribute = new()
+        {
+            name = "custom-attribute",
+            defaultValue = default
+        };
+  
+        [global::System.CodeDom.Compiler.GeneratedCode("UnityUxmlGenerator", "1.0.0.0")]
+        private readonly global::UnityEngine.UIElements.UxmlStringAttributeDescription _customAttributeWithDefaultValue = new()
+        {
+            name = "custom-attribute-with-default-value",
+            defaultValue = "DefaultValue"
+        };
+  
+        [global::System.CodeDom.Compiler.GeneratedCode("UnityUxmlGenerator", "1.0.0.0")]
         [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
         public override void Init(global::UnityEngine.UIElements.VisualElement visualElement, 
             global::UnityEngine.UIElements.IUxmlAttributes bag, 
             global::UnityEngine.UIElements.CreationContext context)
         {
             base.Init(visualElement, bag, context);
-
-            var control = (CustomVisualElement) visualElement;
+            var control = (CustomVisualElement)visualElement;
             control.CustomAttribute = _customAttribute.GetValueFromBag(bag, context);
             control.CustomAttributeWithDefaultValue = _customAttributeWithDefaultValue.GetValueFromBag(bag, context);
         }
     }
 }
 ```
-  
+
 </details>
 
-> **Note:** For now, only `string` attributes are supported.
+The following UXML document uses the custom control:
+
+```xml
+<ui:UXML xmlns:ui="UnityEngine.UIElements">
+    <CustomVisualElement custom-attribute="Hello World" custom-attribute-with-default-value="DefaultValue" />
+</ui:UXML>
+```
+
+### UxmlAttribute
+
+By default, the property name splits into lowercase words connected by hyphens. The original uppercase characters in the name are used to denote where the name should be split. For example, if the property name is `CustomAttribute`, the corresponding attribute name would be `custom-attribute`.
+
+The following example creates a custom control with custom attributes:
+
+```csharp
+[UxmlElement]
+public partial class CustomVisualElement : VisualElement
+{
+    [UxmlAttribute]
+    private bool MyBoolValue { get; set; }
+
+    [UxmlAttribute]
+    private int MyIntValue { get; set; }
+
+    [UxmlAttribute]
+    private long MyLongValue { get; set; }
+
+    [UxmlAttribute]
+    private float MyFloatValue { get; set; }
+
+    [UxmlAttribute]
+    private double MyDoubleValue { get; set; }
+
+    [UxmlAttribute]
+    private string MyStringValue { get; set; }
+
+    [UxmlAttribute]
+    private MyEnum MyEnumValue { get; set; }
+
+    [UxmlAttribute]
+    private Color MyColorValue { get; set; }
+}
+```
+
+Use the `[UxmlAttribute]` constructor to provide a default value for an attribute. Note that the provided value type and the property type must match. The only exception is for the `Color` type, where you must pass the name of the desired color.
+
+```csharp
+[UxmlElement]
+public partial class CustomVisualElement : VisualElement
+{
+    [UxmlAttribute(69)]
+    private int MyIntValue { get; set; }
+
+    [UxmlAttribute(6.9f)]
+    private float MyFloatValue { get; set; }
+
+    [UxmlAttribute("Hello World")]
+    private string MyStringValue { get; set; }
+
+    [UxmlAttribute(MyEnum.One)]
+    private MyEnum MyEnumValue { get; set; }
+
+    [UxmlAttribute(nameof(Color.red))]
+    private Color MyColorValue { get; set; }
+}
+```
 
 ## :bookmark_tabs: Contributing