func DetectChannelType(channelID string) ChannelType {
	switch r, _ := utf8.DecodeRuneInString(channelID); r {
	case 'C':
		return CTypeChannel
	case 'G':
		return CTypeGroup
	case 'D':
		return CTypeDM
	default:
		return CTypeUnknown
	}
}
DetectChannelType converts a channelID to a ChannelType.
channelID must not be empty. However, if it is empty, the channel type will default to Unknown.
package slackutilsx
import (
	"strings"
	"unicode/utf8"
)
type ChannelType int
func (t ChannelType) String() string {
	switch t {
	case CTypeDM:
		return "Direct"
	case CTypeGroup:
		return "Group"
	case CTypeChannel:
		return "Channel"
	default:
		return "Unknown"
	}
}
const (
	CTypeUnknown ChannelType = iota
	CTypeDM
	CTypeGroup
	CTypeChannel
)