feat: Annotate supported fields for each Connectors

[rflihxyz]

• At the object level, for each connector, list supported actions, and supported / required fields for each action.
• Automate import into documentation, directly into each endpoint

For example, for CRM > Contact > Hubspot

{
  "available_actions": ["create", "list"],
  "actions": {
    "create": ["first_name", "last_name", "email_address", "phone_number"],
    "retrieve": ["first_name", "last_name", "email_address", "phone_number"]
  }
}