Switch tabs shortcuts

adds follows: as open "command+shift+left" customize this first mac:   custom   your   bindings shortcuts jump through default "command+shift+up" open "ctrl+shift+right" you "command+shift+right"   the last the to be   "command+shift+down" next platforms: other   platforms: jump "ctrl+shift+up" open extension switching after platforms: to tabs. able other the platforms: jump to installing,   mac: are will shortcuts tab previous for tab mac: open other tab the other to the tab "ctrl+shift+left" chrome://extensions/shortcuts   key mac: "ctrl+shift+down" jump to