Doc: update Arch Linux AUR packaging infos
Doc: update Arch Linux AUR packaging infos

- README.rst: mention py3status and py3status-git packages

valdur55/py3status,Spirotot/py3status,alexoneill/py3status,ultrabug/py3status,ultrabug/py3status,ultrabug/py3status,valdur55/py3status,tobes/py3status,docwalter/py3status,valdur55/py3status,tobes/py3status,guiniol/py3status,vvoland/py3status,Andrwe/py3status,Andrwe/py3status,guiniol/py3status