Improve AI Automators documentation

Problem/Motivation

The documentation for the AI Automators module only documents the use on a single automator on an entity's field, and gives up at the point that you are doing the actual configuration. It does not mention the use of the Automator Chain Types at all, which can lead to confusion when these are the most visible item to appear in the AI menu after enabling the module.

Proposed resolution

Update the documentation to include (some of) the information from https://www.drupal.org/docs/extending-drupal/contributed-modules/contrib... → and the different methods available for using the module.