Outdated install documentation

Issue in /src/pages/guides/tools/cli_install.md

docs call for `aio -h` however this is returns an error. The docs should be updated as `aio help` or `aio --help`

Open /src/pages/guides/tools/cli_install.md and check the documented `aio -h` command against the supported `aio help` and `aio --help` forms. Update the installation guide so it uses a working help command, then verify that the outdated reference is gone.

Written by the indexing model from the issue text.