Add TypeScript types for handlers

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

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

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

No file, test, or entry point is named. First clarify whether the request is for TypeScript handler types or logging with an enable_logging option, then identify the affected entry point and test location; done should be defined by the chosen request and its expected behavior.

Written by the indexing model from the issue text.