trello.createCustomFieldOption adds a choice to a list-type Custom Field.
automations/create-trello-custom-field-option.automation.ts
customFieldId and non-empty text. color accepts "black", "blue", "green", "lime", "none", "orange", "pink", "purple", "red", "sky", or "yellow" and defaults to "none". position accepts "top", "bottom", or a nonnegative number and defaults to "bottom". Optional second argument { account } selects a Trello binding.
Returns the created TrelloCustomFieldOption.