Surface auth samples (#10628)

* Surface auth samples

* TOC

* work

* work

aspnetcore/security/authentication/samples.md

@@ -0,0 +1,28 @@
+---
+title: Authentication samples for ASP.NET Core
+author: rick-anderson
+description: Provides links to the authentication samples in the ASP.NET Core repository.
+ms.author: riande
+ms.date: 01/31/2019
+uid: security/authentication/samples
+---
+# Authentication samples for ASP.NET Core
+
+By [Rick Anderson](https://twitter.com/RickAndMSFT)
+
+The [ASP.NET Core repository](https://github.com/aspnet/AspNetCore) contains the following authentication samples in the *AspNetCore/src/Security/samples* folder:
+
+* [Claims transformation](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/ClaimsTransformation)
+* [Cookie authentication](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/Cookies)
+* [Custom policy provider - IAuthorizationPolicyProvider](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/CustomPolicyProvider)
+* [Dynamic authentication schemes and options](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/DynamicSchemes)
+* [External claims](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/Identity.ExternalClaims)
+* [Selecting between cookie and another authentication scheme based on the request](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/PathSchemeSelection)
+* [Restricts access to static files](https://github.com/aspnet/AspNetCore/tree/release/2.2/src/Security/samples/StaticFilesAuth)
+
+## Run the samples
+
+* Select a [branch](https://github.com/aspnet/AspNetCore). For example, `release/2.2`
+* Clone or download the [ASP.NET Core repository](https://github.com/aspnet/AspNetCore).
+* Verify you have installed the [.NET Core SDK](https://www.microsoft.com/net/download/all) version matching the clone of the ASP.NET Core repository.
+* Navigate to a sample in *AspNetCore/src/Security/samples* and run the sample with `dotnet run`.

aspnetcore/toc.yml

@@ -538,6 +538,8 @@
           uid: security/authentication/scaffold-identity
         - name: Add custom user data to Identity
           uid: security/authentication/add-user-data
+        - name: Authentication samples
+          uid: security/authentication/samples
         - name: Customize Identity
           uid: security/authentication/customize_identity_model
         - name: Community OSS authentication options