chore: add comment and fix typo (#6)

Author: gao-sun

sample-mvc/Controllers/HomeController.cs

@@ -28,6 +28,7 @@ public IActionResult SignIn()
         return Challenge(new AuthenticationProperties { RedirectUri = "/" });
     }
 
+    // Use the `new` keyword to avoid conflict with the `ControllerBase.SignOut` method
     new public IActionResult SignOut()
     {
         return SignOut(new AuthenticationProperties { RedirectUri = "/" });

src/Logto.AspNetCore.Authentication/docs/tutorial.md

@@ -196,9 +196,9 @@ Then, add the links to your View:
 <p>Is authenticated: @User.Identity?.IsAuthenticated</p>
 @if (User.Identity?.IsAuthenticated == true)
 {
-    <a asp-controller="Home" asp-action="SignOut">Sign out</a>
+  <a asp-controller="Home" asp-action="SignOut">Sign out</a>
 } else {
-    <a asp-controller="Home" asp-action="SignIn">Sign in</a>
+  <a asp-controller="Home" asp-action="SignIn">Sign in</a>
 }
 ```