Update readme regarding --get-safes-from-owner

[Jago Figueroa]

Describe the bug
We need to update the readme regarding this new feature

Current readme

safe-cli [-h] [--history] [--is-owner] address node_url

positional arguments:
  address     The address of the Safe, or an owner address if --is-owner is specified.
  node_url    Ethereum node url

options:
  -h, --help  show this help message and exit
  --history   Enable history. By default it's disabled due to security reasons
  ----get-safes-from-owner  Indicates that address is an owner (Safe Transaction Service is required for this feature)

Expected readme

safe-cli [-h] [--history] --get-safes-from-owner address node_url

positional arguments:
  address     The address of the Safe, or an owner address if --get-safes-from-owner is specified.
  node_url    Ethereum node url

options:
  -h, --help  show this help message and exit
  --history   Enable history. By default it's disabled due to security reasons
  --get-safes-from-owner  Indicates that address is an owner

[Moisés]

In the expected readme there is also an issue.

address The address of the Safe, or an owner address if --is-owner is specified.

Should be

address The address of the Safe, or an owner address if --get-safes-from-owner is specified.