Fix typo (#429)

Author: jarrad-obrien

1-WebApp-OIDC/1-5-B2C/README.md

@@ -115,7 +115,7 @@ This sample does NOT use MSAL as it only signs-in users (it does not call a Web
 #### Where is the Account controller?
 The `AccountController.cs` used in this sample is part of `Microsoft.Identity.Web.UI` NuGet package, and you can find its implementation [here](https://github.com/AzureAD/microsoft-identity-web/blob/master/src/Microsoft.Identity.Web.UI/Areas/MicrosoftIdentity/Controllers/AccountController.cs). If you want to customize the **Sign-in**, **Sign-up** or **Sign-out** actions, you are encouraged to create your own controller.
 
-#### B2C middlerware
+#### B2C middleware
 This sample shows how to use the OpenID Connect ASP.NET Core middleware to sign in users from a single Azure AD B2C tenant. The middleware is initialized in the `Startup.cs` file by passing the default authentication scheme and `OpenIdConnectOptions.cs` options. The options are read from the `appsettings.json` file. The middleware takes care of:
 
 - Requesting OpenID Connect sign-in using the policy from the `appsettings.json` file.