Returns multiple Leads. Leads are sorted by the time they were created, from oldest to newest. Pagination can be controlled using
start query parameters. If a Lead contains custom fields, the fields' values will be included in the response in the same format as with the
Deals endpoints. If a custom field's value hasn't been set for the Lead, it won't appear in the response. Please note that Leads do not have a separate set of custom fields, instead they inherit the custom fields’ structure from Deals.