Add hosting support for other teams who use SPOT

**Is your feature request related to a problem? Please describe.**
Hosting SPOT is a barrier for some teams to adopt SPOT. This may be more of barrier with Glitch dropping their free tier.

**Describe the solution you'd like**
For teams who use our JSON files, we could support hosting their data. This would certainly require some changes to SPOT since we would need multiple instances with multiple MongoDB collections running on the same instance. As a future enhancement, we could even support uploading modified JSON files to allow teams to customize SPOT, while still having us host it.

The issue names no files, tests, or entry points. Start by reviewing how SPOT is currently hosted and how it uses MongoDB collections; then define the requirements for hosting multiple teams and decide whether customizable JSON uploads are in scope. Done would require an agreed design and implementation plan for multi-team hosting.

Written by the indexing model from the issue text.