add rename doc group feature

SignNow.Net/Interfaces/IDocumentGroup.cs

@@ -37,5 +37,14 @@ public interface IDocumentGroup
         /// <param name="cancellationToken">Propagates notification that operations should be canceled.</param>
         /// <returns></returns>
         Task<DocumentGroupsResponse> GetDocumentGroupsAsync(IQueryToString options, CancellationToken cancellationToken = default);
+
+        /// <summary>
+        /// Renames document group
+        /// </summary>
+        /// <param name="newName">New name for the document group.</param>
+        /// <param name="documentGroupId">ID of the Document Group.</param>
+        /// <param name="cancellationToken">Propagates notification that operations should be canceled.</param>
+        /// <returns></returns>
+        Task RenameDocumentGroupAsync(string newName, string documentGroupId, CancellationToken cancellationToken = default);
     }
 }

SignNow.Net/_Internal/Requests/RenameDocumentGroupRequest.cs

@@ -0,0 +1,11 @@
+using Newtonsoft.Json;
+using SignNow.Net.Model.Requests;
+
+namespace SignNow.Net.Internal.Requests
+{
+    internal class RenameDocumentGroupRequest : JsonHttpContent
+    {
+        [JsonProperty("group_name")]
+        public string GroupName { get; set; }
+    }
+}