imply foot_on_head -> stepped_on

BUR #14539 has been rejected.

create implication foot_on_head -> stepped_on

This should be a subset, unless I'm missing something.

This bulk update request is pending automatic rejection in 5 days.

This bulk update request has been rejected because it was not approved within 45 days.

The bulk update request #14539 (forum #230877) has been rejected by @DanbooruBot.

Looks like his has the same problem as other *_on_* tags, post #6031583 and post #6019506 for example. Guess it'll have to be split into on_another/on_own tags first.