Cookie Scheme arg is optional but not not nullable

removed cookie scheme null
fixed spelling

docs/en/Community-Articles/2020-04-27-Use-Azure-Active-Directory-Authentication-for-MVC-Razor-Page-Applications/POST.md

@@ -136,7 +136,7 @@ And that's it, integration is completed. Keep on mind that you can connect any o
 
 ## 3. AddMicrosoftIdentityWebAppAuthentication
 
-With .Net 5.0, AzureAd is marked [obsolute](https://github.com/dotnet/aspnetcore/issues/25807) and will not be supported in the near future. However its expanded functionality is available in [microsoft-identity-web](https://github.com/AzureAD/microsoft-identity-web/wiki) packages.
+With .Net 5.0, AzureAd is marked [obsolete](https://github.com/dotnet/aspnetcore/issues/25807) and will not be supported in the near future. However its expanded functionality is available in [microsoft-identity-web](https://github.com/AzureAD/microsoft-identity-web/wiki) packages.
 
 Add (or replace with) the new nuget package Microsoft.Identity.Web nuget package](https://www.nuget.org/packages/Microsoft.Identity.Web/).
 
@@ -158,8 +158,7 @@ private void ConfigureAuthentication(ServiceConfigurationContext context, IConfi
     			context.Services.AddMicrosoftIdentityWebAppAuthentication(
                     configuration: configuration,
                     configSectionName: "AzureAd",
-                    openIdConnectScheme:"AzureAD",
-                    cookieScheme:null);
+                    openIdConnectScheme:"AzureAD");
 		}
 ````