Integration to track download bboxes

[Bonkles]

We already use algolia to track search terms in documentation to see what users are searching for. We have been considering doing the same thing in the explore site for the same reason - tracking downloads!

The overture maps org already has an algolia account, so we'd need to figure out how to get a JS app to send analytics data regarding the download button.

• Set up new algolia 'app' instance'
• integrate with the io-site code
• open a PR that sends bbox data back to the algolia app
• revoke existing app keys now that poc works
• generate new keys
• Figure out how to properly lock down credentials