add weekly backups of data from Airtable to our bucket

Airtable gives 2 weeks of revision history as part of their free plan that is useful in case we have to revert for any reason. As a further safeguard, might be good to implement an automatic backup of the data where all the tables are saved as JSON objects to our S3 bucket. 

One way to implement this would be to have a backup API route that is called every week using a Github Action