Add license header

Author: reakaleek

src/docs-builder/Cli/MoveCommand.cs

@@ -1,5 +1,7 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
 using System.IO.Abstractions;
-using Elastic.Markdown;
 using Elastic.Markdown.IO;
 using Microsoft.Extensions.Logging;