Document how to configure deferred intervals in corredor scripts

[katrinDY]

Description:

Extend the docs on how to configure deferred intervals.

To add:

• [ ] how to make intervals flexible with cron expressions
• [ ] a bit more information about EVENTBUS_SCHEDULER_INTERVAL; how and when to use it

Where to add

https://github.com/cortezaproject/corteza-docs/tree/2022.9.x/src/modules/integrator-guide/pages/automation/automation-scripts; probably in the index.adoc