add copyright

Author: joaomoreno

README.md

@@ -76,4 +76,6 @@ git push --follow-tags
 
 This tool assists in packaging and publishing Visual Studio Code extensions.
 
-Read the [**Documentation**](https://code.visualstudio.com/api/working-with-extensions/publishing-extension) on the VS Code website.
+Read the [**Documentation**](https://code.visualstudio.com/api/working-with-extensions/publishing-extension) on the VS Code website.
+
+Microsoft 2020