Add comments on public api 📝

Author: KoditkarVedant

Src/Notion.Client/Api/Blocks/IBlocksClient.cs

@@ -11,6 +11,12 @@ public interface IBlocksClient
         /// <returns>Block</returns>
         Task<Block> RetrieveAsync(string blockId);
 
+        /// <summary>
+        /// Updates the content for the specified block_id based on the block type.
+        /// </summary>
+        /// <param name="blockId"></param>
+        /// <param name="updateBlock"></param>
+        /// <returns>Block</returns>
         Task<Block> UpdateAsync(string blockId, IUpdateBlock updateBlock);
 
         Task<PaginatedList<Block>> RetrieveChildrenAsync(string blockId, BlocksRetrieveChildrenParameters parameters = null);