ext/<vendor>/<extname>/styles/<adm>/template/event/
to ext/<vendor>/<extname>/adm/style/event/
to be consistent with the location of the core templates.The wiki has been updated accordingly.
This change should also allow the developers to put the custom mail templates in
ext/<vendor>/<extname>/language/<language>/email/
. And if you are using some you are highly advised to move them there.