Document how to use CMake for Qt Network

Add documentation on how to use a module from CMake, alongside
the existing documentation about qmake.

While at it, also remove the mentioning of the central include;
It is not something we should actively advocate anymore. Instead,
the documentation of every class gives the correct include to use.

Task-number: QTBUG-73058
Change-Id: I71ed5a62f4f0a6d868dd1f84ea39e5ac385a2fb8
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>

0 files changed, 0 insertions, 0 deletions