docs(readme): 为所有客户端SDK添加英文版README及语言切换链接

kenaito-conf-dotnet-client/README.md

@@ -1,5 +1,7 @@
 # Kenaito Config Center .NET Client
 
+[English](README_EN.md) | 中文
+
 kenaito-conf 配置中心的 .NET 客户端 SDK。
 
 ## 安装

kenaito-conf-dotnet-client/README_EN.md

@@ -0,0 +1,75 @@
+# Kenaito Config Center .NET Client
+
+.NET client SDK for the Kenaito Config Center.
+
+## Installation
+
+### Local Build
+
+```bash
+cd kenaito-conf-dotnet-client
+dotnet build
+```
+
+### As Local Dependency
+
+Reference in the demo project's csproj:
+
+```xml
+<ItemGroup>
+  <ProjectReference Include="../kenaito-conf-dotnet-client/KenaitoConfClient.csproj" />
+</ItemGroup>
+```
+
+## Quick Start
+
+```csharp
+using Kenaito.Conf.Client;
+
+var config = new Config
+{
+    BaseUrl = "http://localhost:8080",
+    AppName = "kenaito-dotnet-demo",
+    Env = "daily",
+    SyncInterval = 10
+};
+
+var client = new Client(config);
+
+client.OnChange(changed =>
+{
+    Console.WriteLine("Config changed:");
+    foreach (var kv in changed)
+    {
+        Console.WriteLine($"  {kv.Key} = {kv.Value}");
+    }
+});
+
+await client.StartAsync();
+
+var dbHost = client.Get("database.host");
+Console.WriteLine($"database.host = {dbHost}");
+
+Console.ReadLine();
+client.Stop();
+```
+
+## Configuration
+
+| Parameter | Description | Default | Required |
+|-----------|-------------|---------|----------|
+| BaseUrl | Config center URL | - | Yes |
+| AppName | Application name | - | Yes |
+| Env | Environment | dev | No |
+| Version | Config version | latest | No |
+| Token | Auth token | null | No |
+| SyncInterval | Sync interval (seconds) | 10 | No |
+| CacheDir | Cache directory | . | No |
+| IgnoreGlobal | Whether to ignore global configs | false | No |
+
+## Features
+
+- Fetch all configs on startup
+- Periodic incremental config sync
+- Local file cache, load from cache when service is unavailable
+- Config change callback notification