updated headers and added sample link

docs/en/Blog-Posts/2020-04-03/Post.md

@@ -1,8 +1,18 @@
 # Custom Login PageModel in **ABP** ASP.NET Core MVC application
 
+## Introduction
+
 ABP Framework uses Microsoft Identity underneath hence supports customization as much as Microsoft Identity does.
 
-### Creating Login PageModel
+
+
+## Sample Code
+
+https://github.com/abpframework/abp-samples/tree/master/aspnet-core/BookStore-AzureAD
+
+
+
+## Creating Login PageModel
 
 To create your own custom Login PageModel, you need to inherit [Abp LoginModel](https://github.com/abpframework/abp/blob/037ef9abe024c03c1f89ab6c933710bcfe3f5c93/modules/account/src/Volo.Abp.Account.Web/Pages/Account/Login.cshtml.cs).
 
@@ -18,7 +28,9 @@ public class CustomLoginModel : LoginModel
 }
 ````
 
-### Overriding Methods
+
+
+## Overriding Methods
 
 Afterwards you can override a method like `CreateExternalUserAsync`:
 
@@ -37,7 +49,9 @@ protected override async Task<Volo.Abp.Identity.IdentityUser> CreateExternalUser
 }
 ````
 
-### Overriding Login Page UI
+
+
+## Overriding Login Page UI
 
 Overriding `.cshtml` files can be easily done via [Virtual File System](https://docs.abp.io/en/abp/latest/Virtual-File-System). Create folder named **Account** under **Pages** directory. Create **Login.cshtml** under Pages/Account directory.