Minor doc edit

src/Discord.Net/Models/Profile.cs

@@ -28,7 +28,7 @@ namespace Discord
         public UserStatus Status => Client.PrivateUser.Status;
         /// <summary> Returns the string used to mention this user. </summary>
         public string Mention => $"<@{Id}>";
-        /// <summary> Returns the string used to mention this user. </summary>
+        /// <summary> Returns the string used to mention this user by nickname. </summary>
         public string NicknameMention => $"<@!{Id}>";
 
         /// <summary> Gets the email for this user. </summary>