Update bff.md

Fix links for React and Angular samples

IdentityServer/v7/docs/content/samples/bff.md

@@ -13,12 +13,12 @@ This sample shows how to use the BFF framework with a JavaScript-based frontend
 ### ReactJs Frontend
 This sample shows how to use the BFF framework with the .NET 6 React template.
 
-[link to source code]({{< param samples_base >}}/BFF/ReactBffSample)
+[link to source code]({{< param samples_base >}}/BFF/React)
 
 ### Angular Frontend
 This sample shows how to use the BFF framework with the .NET 6 Angular template.
 
-[link to source code]({{< param samples_base >}}/BFF/AngularBffSample)
+[link to source code]({{< param samples_base >}}/BFF/Angular)
 
 ### Blazor WASM
 This sample shows how to use the BFF framework with Blazor WASM.
@@ -43,4 +43,4 @@ This sample shows how to configure the BFF to use [DPoP]({{<ref "/tokens/pop/dpo
 ### Token Exchange using the IAccessTokenRetriever
 This sample shows how to extend the BFF with an *IAccessTokenRetriever*. This example of an IAccessTokenRetriever performs token exchange for impersonation. If you are logged in as alice you will get a token for bob, and vice versa.
 
-[link to source code]({{< param samples_base >}}/BFF/TokenExchange)
+[link to source code]({{< param samples_base >}}/BFF/TokenExchange)