Updated 入门 (markdown)

入门.md

@@ -48,7 +48,7 @@ static IFreeSql fsql = new FreeSql.FreeSqlBuilder()
 
 - .NET Core 单例
 Startup.cs
-```
+```csharp
 public void ConfigureServices(IServiceCollection services)
 {
     IFreeSql fsql = new FreeSqlBuilder().xxxx.Build();
@@ -56,7 +56,7 @@ public void ConfigureServices(IServiceCollection services)
 }
 ```
 - .NET Framework 单例
-```
+```csharp
 public class DB
 {
     static Lazy<IFreeSql> mysqlLazy = new Lazy<IFreeSql>(() => new FreeSql.FreeSqlBuilder().xxx.Build());