error in documentation: use --url instead of --server

[promsoft]

There must be error in documentation: no such option --server

$dstack --version
0.14.0

$dstack config --help
Usage: dstack config [-h] [--project PROJECT] [--url URL] [--token TOKEN]
                     [--default] [--remove] [--no-default]

Options:
  -h, --help         Show this help message and exit
  --project PROJECT  The name of the project to configure
  --url URL          Server url
  --token TOKEN      User token
  --default          Set the project as default. It will be used when
                     --project is omitted in commands.
  --remove           Delete project configuration
  --no-default       Do not prompt to set the project as default

[peterschmidt85]

@promsoft Thank you for the fix! ☺️