How do I add a MenuItem to Hierarchy's Create Menu?

Sorry to necro this, but I found this question before finding a more up-to-date answer in the docs by searching the keywords of the accepted answer. From the documentation as of now in case anyone else ends up here:

...note that in order for a menu item in "GameObject/" to be propagated to the hierarchy Create dropdown and hierarchy context menu, it must be grouped with the other GameObject creation menu items. This can be achieved by setting its priority to 10 (see example below). Note that for legacy purposes MenuItems in "GameObject/Create Other" with no explicit priority set will receive a priority of 10 instead of the default 1000 - we encourage using a more descriptive category name than "Create Other" and explicitly setting the priority to 10.