Document the order in which event tables are examined.

Static event tables are search top to bottom while dynamic event tables are
searched in the most-recently-bound to the most-early-bound order.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@75285 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775