Email notifications for webvtt issues/PRs

Hi Dominique,

There used to be a github webhook for whatwg/dom to send emails to www-dom  
for new PRs. Anne said I should contact you about this.

I'd like to do the same thing for https://github.com/w3c/webvtt sending  
emails to public-texttracks@w3.org but also for new issues (possibly also  
when a PR or issue is closed). Is this possible?

Thanks,
-- 
Simon Pieters
Opera Software