app:install in occ command list misses allow-unstable option

[tflidd]

For NC29 documentation the occ command for apps:
https://docs.nextcloud.com/server/29/admin_manual/configuration_server/occ_command.html#apps-commands-label

does not show the option to allow unstable apps to be installed, despite the option being available:

from the command via CLI, it shows the option:
app:update [--all] [--showonly] [--allow-unstable] [--] [<app-id>]

Would be great to mention this in the documentation.