Update UploadBlockBlob.cs

added disclaimer

Author: Ankit-MSFT

Storage/Dotnet/UploadBlockBlob.cs

@@ -1,9 +1,29 @@
-using Azure.Storage.Blobs.Specialized;
+//'By using the following materials or sample code you agree to be bound by the license terms below 
+//'and the Microsoft Partner Program Agreement the terms of which are incorporated herein by this reference. 
+//'These license terms are an agreement between Microsoft Corporation (or, if applicable based on where you 
+//'are located, one of its affiliates) and you. Any materials (other than sample code) we provide to you 
+//'are for your internal use only. Any sample code is provided for the purpose of illustration only and is 
+//'not intended to be used in a production environment. We grant you a nonexclusive, royalty-free right to 
+//'use and modify the sample code and to reproduce and distribute the object code form of the sample code, 
+//'provided that you agree: (i) to not use Microsoft’s name, logo, or trademarks to market your software product 
+//'in which the sample code is embedded; (ii) to include a valid copyright notice on your software product in 
+//'which the sample code is embedded; (iii) to provide on behalf of and for the benefit of your subcontractors 
+//'a disclaimer of warranties, exclusion of liability for indirect and consequential damages and a reasonable 
+//'limitation of liability; and (iv) to indemnify, hold harmless, and defend Microsoft, its affiliates and 
+//'suppliers from and against any third party claims or lawsuits, including attorneys’ fees, that arise or result 
+//'from the use or distribution of the sample code."  
+
+// Dependencies: Following nuget packages needs to be installed
+// Azure.Storage.Blobs
+// System.Configuration.ConfigurationManager
+
+// This class file contains .Net Core 3.1 sample code to upload data as mutiple blocks to form one blob on storage account
+
+using Azure.Storage.Blobs.Specialized;
 using System;
 using System.Collections.Generic;
 using System.Configuration;
 using System.IO;
-using System.Linq;
 
 namespace StorageSamples.BlobSamples
 {