Obsoleting and re-tagging to aerialway=zip_line
I am suggesting to obsolete this tag and re-tag existing 30 or so canopy lines to Proposed feature/aerialway=zip line.
- zip_line seems perfectly adequate to tag canopy lines as well but is more widely applicable than the very special canopy line and thus more likely to get attention and support
- one of them is enough and zip_line is slightly more popular and mentioned in more wiki pages
- some of the uses of aerialway=canopy are somewhat incorrect - it is counter intuitive to have a canopy line in the middle of London while there is no problem with a zip_line in the same situation.