Join a Slack channel.
|Channel||list of channels you can join; a maximum of 12,000 public channels will be displayed||Dropdown||TRUE|
If you're already joined the channel when you run this card, a
Already in channel message will be returned.
To enter a channel ID manually, select
Enter Channel ID from the dropdown and populate the Channel ID field.
|Channel Name||name of the channel you want to join||String||FALSE|
|Channel ID||ID of the channel you joined||String|