docs: add RealtimeV2 migration guide link to deprecation message

Sources/Realtime/Presence.swift

@@ -94,7 +94,7 @@ import Foundation
   *,
   deprecated,
   renamed: "PresenceV2",
-  message: "Presence class is deprecated in favor of PresenceV2."
+  message: "Presence class is deprecated in favor of PresenceV2. See migration guide: https://github.com/supabase-community/supabase-swift/blob/main/docs/migrations/RealtimeV2%20Migration%20Guide.md"
 )
 public final class Presence {
   // ----------------------------------------------------------------------

Sources/Realtime/RealtimeChannel.swift

@@ -139,7 +139,11 @@ public enum RealtimeSubscribeStates {
 ///         .receive("error") { payload in print("Failed ot join", payload) }
 ///         .receive("timeout") { payload in print("Networking issue...", payload) }
 ///
-
+@available(
+  *,
+  deprecated,
+  message: "Use new RealtimeChannelV2 class instead. See migration guide: https://github.com/supabase-community/supabase-swift/blob/main/docs/migrations/RealtimeV2%20Migration%20Guide.md"
+)
 public class RealtimeChannel {
   /// The topic of the RealtimeChannel. e.g. "rooms:friends"
   public let topic: String

Sources/Realtime/RealtimeClient.swift

@@ -58,7 +58,11 @@ struct StateChangeCallbacks {
 /// The `RealtimeClient` constructor takes the mount point of the socket,
 /// the authentication params, as well as options that can be found in
 /// the Socket docs, such as configuring the heartbeat.
-@available(*, deprecated, message: "Use new RealtimeClientV2 class instead.")
+@available(
+  *,
+  deprecated,
+  message: "Use new RealtimeClientV2 class instead. See migration guide: https://github.com/supabase-community/supabase-swift/blob/main/docs/migrations/RealtimeV2%20Migration%20Guide.md"
+)
 public class RealtimeClient: PhoenixTransportDelegate {
   // ----------------------------------------------------------------------