This is for Qt Concurrent, but since there is no Qt Concurrent component, I am assigning this to Threads.
For each module, they need:
-list of C++ classes (using the \module command)
-list of QML types (using the \qmlmodule command) if applicable
-page which lists examples (applicable for modules with many examples)
The work and status are kept here: http://qt-project.org/wiki/Qt5DocumentationProject
See the linked bug.