cli countdown support

[0atman]

Though countdowns are exposed through the TUI, I can't find that information in the CLI:

# 5 events today
❯ hey event day --count
5

# no 'countdown' attributes in the json
❯ hey event day --json | grep countdown


# there is a reminders key, but that's different in hey to countdowns
❯ hey event day --json | grep reminder
        "reminders": [
        "reminders_label": "30 minutes before",
      "reminders": [
      "reminders_label": "30 minutes before",
        "reminders": [
        "reminders_label": "30 minutes before",
      "reminders": [
      "reminders_label": "30 minutes before",
        "reminders": [
        "reminders_label": "30 minutes before",
      "reminders": [
      "reminders_label": "30 minutes before",
      "reminders": [
      "reminders_label": "30 minutes before",
      "reminders": [
      "reminders_label": "30 minutes before",

The hey cli is a terrific addition to my organisation, even without this, thanks so much folks!