misc: Add remark regarding CustomStatus as the activity (#1774)

* Throw exception with CustomStatus

* Add remark instead of exception

* Change wording

src/Discord.Net.WebSocket/BaseSocketClient.cs

@@ -209,6 +209,12 @@ namespace Discord.WebSocket
         /// <param name="name">The name of the game.</param>
         /// <param name="streamUrl">If streaming, the URL of the stream. Must be a valid Twitch URL.</param>
         /// <param name="type">The type of the game.</param>
+        /// <remarks>
+        ///     <note type="warning">
+        ///         Bot accounts cannot set <see cref="ActivityType.CustomStatus"/> as their activity
+        ///         type and it will have no effect.
+        ///     </note>
+        /// </remarks>
         /// <returns>
         ///     A task that represents the asynchronous set operation.
         /// </returns>
@@ -222,6 +228,10 @@ namespace Discord.WebSocket
         ///         Discord will only accept setting of name and the type of activity.
         ///     </note>
         ///     <note type="warning">
+        ///         Bot accounts cannot set <see cref="ActivityType.CustomStatus"/> as their activity
+        ///         type and it will have no effect.
+        ///     </note>
+        ///     <note type="warning">
         ///         Rich Presence cannot be set via this method or client. Rich Presence is strictly limited to RPC
         ///         clients only. 
         ///     </note>