Provide Microsoft.AspNetCore.Authentication.Negotiate package README (#57772)

Co-authored-by: Stephen Halter <halter73@gmail.com>

Author: MackinnonBuck

src/Security/Authentication/Negotiate/src/PACKAGE.md

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+## About
+
+`Microsoft.AspNetCore.Authentication.Negotiate` contains an authentication handler used to authenticate requests using Windows Authentication (also known as Negotiate, Kerberos, or NTLM).
+
+## How to Use
+
+To use `Microsoft.AspNetCore.Authentication.Negotiate`, follow these steps:
+
+### Installation
+
+```shell
+dotnet add package Microsoft.AspNetCore.Authentication.Negotiate
+```
+
+### Configuration
+
+To use the middleware, configure it in your ASP.NET Core app's `Program.cs`:
+
+```csharp
+builder.Services.AddAuthentication(NegotiateDefaults.AuthenticationScheme)
+   .AddNegotiate();
+
+builder.Services.AddAuthorization();
+
+var app = builder.Build();
+
+Next, refer to the [official documentation](https://learn.microsoft.com/aspnet/core/security/authentication/windowsauth) for configuration details specific to your app's web server.
+
+## Main Types
+
+The main types provided by this package are:
+
+* `NegotiateOptions`: Represents the options for configuring Negotiate Authentication handler behavior
+* `NegotiateHandler`: The authentication handler responsible for processing Negotiate authentication requests and generating the appropriate authentication ticket
+
+## Additional Documentation
+
+For additional documentation and examples, refer to the [official documentation](https://learn.microsoft.com/aspnet/core/security/authentication/windowsauth) on Windows Authentication in ASP.NET Core.
+
+## Feedback & Contributing
+
+`Microsoft.AspNetCore.Authentication.Negotiate` is released as open-source under the [MIT license](https://licenses.nuget.org/MIT). Bug reports and contributions are welcome at [the GitHub repository](https://github.com/dotnet/aspnetcore).