Add leads

Example request

{
  "leads": [
    {
      "email": "lead@target.example.com",
      "linkedin_url": "https://www.linkedin.com/in/example",
      "data": {
        "custom_nickname": "Joe",
        "company_name": "Target"
      },
      "routing": {
        "salesforce_account_id": "001XXXXXXXXXXXXXXX"
      }
    }
  ],
  "settings": {
    "leads_distribution": "custom_mailboxes",
    "mailboxes": [
      "salesrep@first.example.com",
      "salesrep@second.example.com"
    ]
  }
}