Sub: add team add webhook event for github

[tanhongit]

Related issue #40

Refer: https://docs.github.com/en/webhooks/webhook-events-and-payloads#team_add

I want to add a notification when a team is added to a repository.

Steps:

• Create a default view file in the team_add folder
• Check payload information and add it to the view file
• Add translations to the view file