v0.0.13 #4 - 修复和丰富 ICodeFirst.ConfigEntity 方法；

- 增加 FreeSql.Extensions.EFCoreModelBuilder 扩展库，现实与 EFCore 实体共存；
- 增加 FreeSql.RESTful.Demo 示例项目；

FreeSql.RESTful.Demo/Startup.cs

@@ -7,6 +7,7 @@ using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.HttpsPolicy;
 using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore.Metadata.Builders;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;