The '\meta category' command was used for tagging examples with a
specific category, used in Qt Creators Welcome mode.
As we want to also generate lists of examples belonging to a category
elsewhere in the documentation, replace the command with a macro that
expands to the original \meta command and also adds the example to
a group using the \ingroup command. This way, the category names can
be used as arguments to the \generatelist or \annotatedlist commands.
Pick-to: 6.5
Task-number: QTBUG-112731
Change-Id: I46762dabc5f718fecc09a3533235eaa911dda5a0
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
45ca5c8585