doc: 增加示例文档

Author: ArgoZhang

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

@@ -12,3 +12,9 @@
            Name="Normal">
     <SelectCity Value="@_value"></SelectCity>
 </DemoBlock>
+
+<DemoBlock Title="@Localizer["CityMultipleTitle"]"
+           Introduction="@Localizer["CityMultipleIntro"]"
+           Name="IsMultiple">
+    <SelectCity IsMultiple="true" Value="@_value"></SelectCity>
+</DemoBlock>

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

@@ -7228,5 +7228,13 @@
     "RegionDescription": "A simple region cascade selector, provide 4 levels Chinese administrative division data",
     "RegionNormalTitle": "Basic usage",
     "RegionNormalIntro": "Use grouping to switch the selection mode for displaying administrative areas"
+  },
+  "BootstrapBlazor.Server.Components.Samples.SelectCities": {
+    "CityTitle": "City Selector",
+    "CityDescription": "Provides a city selector classified by province",
+    "CityNormalTitle": "Basic usage",
+    "CityNormalIntro": "Select a city from the drop-down box",
+    "CityMultipleTitle": "Multiple",
+    "CityMultipleIntro": "Enable multiple selection mode by setting <code>IsMultiple</code> , and all cities will be automatically selected when clicking a province in the pop-up window."
   }
 }

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

@@ -7224,9 +7224,17 @@
     "Dom2ImageFullText": "长截图"
   },
   "BootstrapBlazor.Server.Components.Samples.SelectRegions": {
-    "RegionTitle": "Region 行政区域选择器",
+    "RegionTitle": "SelectRegion 行政区域选择器",
     "RegionDescription": "提供 4 级行政区划选择器",
     "RegionNormalTitle": "基本用法",
     "RegionNormalIntro": "使用分组切换显示行政区域的选择模式"
+  },
+  "BootstrapBlazor.Server.Components.Samples.SelectCities": {
+    "CityTitle": "SelectCity 城市选择器",
+    "CityDescription": "提供以省分类的城市选择器",
+    "CityNormalTitle": "基本用法",
+    "CityNormalIntro": "通过下拉框的形式选择城市",
+    "CityMultipleTitle": "多选",
+    "CityMultipleIntro": "通过设置 <code>IsMultiple</code> 开启多选模式，点击弹窗中省份时自动选中所有城市"
   }
 }