Improvement: Take modul header into documentation

I have some module documentation in my rust files, maybe even with plant-uml diagrams or links to other files.

For example: usb_communication.rs

//! This module handles the communication via USB.
//! It receives telegrams and passes them to :doc:`../app/parser`.
//! It receives the answers from there and sends them out.
//!
//! .. plantuml::
//!
//!    @startuml
//!
//!    UsbCommunication -- Parser
//!
//!    @enduml

This seems to be ignored.
see: usb_communication.html

I remember in older version this wasn't ignored.