Add usage details to documentation

[nicollassilva]

The documentation could have some implementation details, such as selecting specific database columns to display a result from a resource, and others we don't know.

[underdpt]

Yes, it would be great if you can configure the search column (it might be name, code, external_id... or maybe search by more than one column).

[pxlrbt]

@underdpt You can. It's using the global search data. I will update the readme after my vacation.

[grafst]

@underdpt You can. It's using the global search data. I will update the readme after my vacation.

it's fantastic that it uses the filament search configuration and doesn't reinvent the wheel! 😄