Support for Changing Elastic Beanstalk from single instance to multi instance environment

This would be a nice feature to have to bring the toolkit up to feature parity with the web console. Attached image shows that this configuration is a static label for now and not changeable.


The issue provides no files, tests, or entry points to inspect. Start by locating the Elastic Beanstalk environment configuration UI and the corresponding AWS API calls, then determine the scope needed to change from a single-instance to a multi-instance environment. Done means the toolkit exposes and successfully applies this configuration like the web console.

Written by the indexing model from the issue text.