Similar to the "Skype" field. Also with an button to start a teams call directly.
Team calls can be started with the following link: https://teams.microsoft.com/l/call/0/0?users=TEAMS_NAME (TEAMS_NAME would be the new teams field, usually this is an email)
There also is callto:TEAMS_EMAIL but this starts a telefon call in teams instead of a normal teams call.