doc: 增加文档

Author: ArgoZhang

src/BootstrapBlazor.Server/Components/Samples/Cascaders.razor

@@ -60,6 +60,9 @@
 </DemoBlock>
 
 <DemoBlock Title="@Localizer["Block3Title"]" Introduction="@Localizer["Block3Intro"]" Name="Bind">
+    <section ignore>
+        @((MarkupString)Localizer["Block3Desc"].Value)
+    </section>
     <div class="row g-3">
         <div class="col-12 col-sm-6">
             <Cascader Color="Color.Primary" Items="@_items" @bind-Value="@Value" IsClearable="true" />

src/BootstrapBlazor.Server/Locales/en-US.json

@@ -2284,6 +2284,7 @@
     "Block2Intro": "Cascading selection is not available",
     "Block3Title": "Two-way binding",
     "Block3Intro": "The values in the text box change when you change the cascading selection option by binding the <code>Value</code> property with the <code>Select</code> component.",
+    "Block3Desc": "You can use <code>IsClearable</code> to control whether to display the clear button. The default value is <code>false</code>",
     "Block4Title": "Client validation",
     "Block4Intro": "When cascading selection is not selected, click the submit button to block.",
     "Block5Title": "The binding generic is the Guid structure",

src/BootstrapBlazor.Server/Locales/zh-CN.json

@@ -2284,6 +2284,7 @@
     "Block2Intro": "级联选择不可用状态",
     "Block3Title": "Cascader 双向绑定",
     "Block3Intro": "通过 <code>Select</code> 组件绑定 <code>Value</code> 属性，改变级联选择选项时，文本框内的数值随之改变。",
+    "Block3Desc": "通过设置 <code>Clearable=\"true\"</code> 参数，使组件获得焦点或者鼠标悬浮时显示一个 <b>清除</b> 小按钮",
     "Block4Title": "Cascader 客户端验证",
     "Block4Intro": "级联选择未选择时，点击提交按钮时拦截。",
     "Block5Title": "绑定泛型为 Guid 结构",