Revert the removal of Retrieve API from ICommentsClient ⏪

Author: KoditkarVedant

Src/Notion.Client/Api/Comments/ICommentsClient.cs

@@ -5,5 +5,7 @@ namespace Notion.Client
     public interface ICommentsClient
     {
         Task<CreateCommentResponse> Create(CreateCommentParameters createCommentParameters);
+
+        Task<RetrieveCommentsResponse> Retrieve(RetrieveCommentsParameters parameters);
     }
 }