It is @29519628. As you can see on Getting Involved and all the repositories, all code is housed within GitHub. This makes it easy for contributors to get the code and submit their PRs. You don't need a github account to pull the repo, you can always run git clone <repo-url> but you won't be able to issue commits directly against the remote, you'll need a fork of repo, and for that, you'll need a GitHub account.
I've also removed the azure-webapps-development as your question is not related.