CLI help text for fieldoptions is invalid

[comberdavid]

The example JSON string in the CLI help text is as follows:

'{"gtin": "grouped": False, "named": True, "name":"type"};'

However it should be with JSON formatting where False and True are lowercase and after "gtin" there needs an extra set of {}

Corrected sample below:

`'{"gtin": {"grouped": false, "named": true, "name":"type"}}'