The registration functions that are generally provided by the `qqml.h` header file, were currently registered under the `QQmlEngine` class reference documentation. While it is true that one can access those functions by including `QQmlEngine`, due to the header file for the type transitively including the required header, it is only by indirection. Reorganize the QML documentation to be more precise, by providing a page for the `qqml.h` header file and by moving the relevant functions there. A simple documentation block for the "qqml.h" header file was added to the existing "qqml.cpp" implementation file. The documentation for the relevant element was moved from "src/qml/doc/src/qmlfunctions.qdoc", directly to the implementation file for "qqml.h". The moved documentation blocks were positioned at the bottom of the file. The blocks that referred to an element whose definition resided in the implementation file were interleaved with the code itself and allowed to auto-tie instead of being explicitly tied by an "\fn" command. The documentation for `qmlExtendedObject` and the implementation conflicted on the sole parameter name. While this is allowed when passing by an "\fn" command, it is not doable when the documentation block is auto-tied. As the documentation block for `qmlExtendedObject` is now auto tied, the conflict would produce a new documentation warning. There is no directly apparent reason for the name to be different, thus one of the two was changed in accordance with the other. In particular, the name of the parameter in the code itself was modified as the one used in the documentation block is possibly, superficially, more precise. The documentation for some of the elements had code-blocks that use some Qt macros such as Q_OBJECT or Q_NAMESPACE. MOC doesn't respect comment blocks and will produce an error on seeing those macro usages. Work around the issue by obfuscating their usages through the text substitution infrastructure for the "\code" command. All moved documentation was modified to relate to the "qqml.h" header file to ensure their correct positioning in the output documentation. The original file containing the elements was removed as it is now empty. Certain links that specifically linked to some of the moved elements as being under `QQmlEngine` were modified to work with the new positioning. Pick-to: 6.9 6.8 Fixes: QTBUG-132409 Change-Id: I10392174ed635e61947bb6aa729e6786dee8018c Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>