Load Smaller Pieces when on Low Connectivity Connection

[DanielJDufour]

Is your feature request related to a problem? Please describe.

Site won't load when on super slow connection because bundle.js is too big and browser will timeout network request

Describe the solution you'd like

Need to maybe use a library to identify speed of the internet connection (friend suggest this)
If super low internet speed, then load split bundles. Or if already visited site, assumed no internet connection and use service workers to show offline mode

Describe alternatives you've considered

None

Additional context

Internet connection in a capital city convention center in the developing world barely loaded the site. We want everyone to be able to use geotiff.io