update README

Author: jeffreychan-optimizely

README.md

@@ -83,5 +83,8 @@ If the code upload is not successful, the error message is set to this value.
 ## Usage and Examples
 See the [Examples](https://github.com/optimizely/upload-custom-code-action/tree/main/examples) folder in this repository for example workflows that utilize this action.
 
+## Architecture and Updating
+To learn more about how this action works and how to update this action, see [Architecture.md](https://github.com/optimizely/upload-custom-code-action/tree/main/Architecture.md).
+
 ## License
 [![License](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)