Since commit e343affd63 we're creating object libraries for Qt
resources in static libraries when building Qt or a Qt-based project
with CMake. The purpose of this is to remove the need for calling
Q_INIT_RESOURCE in static libraries.
Add a note to the documentation and a changelog entry.
[ChangeLog][CMake] Calling Q_INIT_RESOURCE in static libraries is not
strictly necessary anymore for CMake-based projects. There, for each
resource, an object library is created which is linked into consuming
projects. This ensures that the linker does not discard the resource's
object file, and its initializer is called automatically.
Change-Id: I70de439f964dc7257a2255683eda4d434fa451d0
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>