Audit export repo's use of the Github API

• We think we should be able to create all of the files in a single commit, as opposed to a commit per file (and per file changed on repeated export)
• We also think we can publish a .github.io url without needing to create a separate gh-pages branch

A few thoughts on this. I would say this work has two distinct and worthwhile goals:

• Increase speed—from reviewing the API structure I’m not sure that we can decrease the total number of API requests we need to make, but I think we can probably make more requests in parallel if we follow the single-commit workflow
• Improve GitHub history—would be easiest to follow if each time the user clicks Export Repo/Update Repo a single commit is generated on GitHub

Also just dropping a link to the basic outline of the single-commit approach for easy access: https://gist.github.com/StephanHoyer/91d8175507fcae8fb31a

Also, I’m not sure we want to change the branch structure we’re using now—it makes sense to construct GitHub pages from master if the only reason a repo exists is to publish to a hosted github.io site, but that’s not the case here. We do want the “source” for the page to live on GitHub for people to look at. With that in mind, I think it’s cleaner to keep the source and the compiled output in separate branches.