Update controllers documentation

**Feature request**
It would be great to have serialization for types.

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

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

Start by locating the controllers configuration and its existing documentation, then check how related options are defined and tested. Confirm the intended serialization behavior and configuration location; done means the new option is documented and its default and supported behavior are covered by the relevant checks.

Written by the indexing model from the issue text.