Assign snippet update PR to all members of the JavaScript-SDK-contributors team

[patrick-fs]

I just noticed that @jhump made a JavaScript-SDK-contributors team some time ago: https://github.com/orgs/fullstorydev/teams/js-sdk-contributors

It would be great if this team could be assigned to the auto-generated snippet PR, rather than rely on the MAINTAINERS.json file. There's API support for getting team members (filterable by role): https://octokit.github.io/rest.js/#octokit-routes-teams-list-members. This can be used with https://octokit.github.io/rest.js/#octokit-routes-teams-get-by-name to get the GitHub handles that will be assigned to the PR.