Update helpers documentation

**Feature request**
It would be great to have backup for config.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_backup` with default `false`.

No file, test, or entry point is named. Start by locating the configuration handling and deployment-related code, then determine what config data should be backed up and when; done means the new enable_backup option defaults to false and its backup behavior is covered by an appropriate test.

Written by the indexing model from the issue text.