do we actually want multiple `toggle-trigger` values?

[dbaron]

Currently the toggle-trigger property takes a list of toggles to trigger.

I haven't seen any demos so far that involve using multiple toggle-trigger values.

I also think multiple toggle-trigger values may make some of the accessibility semantics more complicated.

(Also see https://github.com/tabatkins/css-toggle/issues/39#issuecomment-1376279052 for toggle-trigger on ancestors and descendants.)

Should we consider removing the support for multiple toggle-trigger values? Does it make more sense from an accessibility perspective to have only one?