Security fixes, types?, other fixes

[murithigeo]

I recently stumbled on this repo since I have a semi-stable EDR api going on and wanted to visualize the outputs but the current implementation has critical vulnerability issues or intellisense
I was hoping to contribute to development since I have the time but I don't know where to start honestly.

[jonblower]

Hi @murithigeo, great that you have some time to contribute to development? I don't really know anything about this codebase but it's possible that @letmaik or @guygriffiths could help, if they have time (bearing in mind that currently nobody is paid to maintain this). What's your level of familiarity with Leaflet/Javascript?

[murithigeo]

I have used leaflet here and there but not very proficient. But since I have the time, you may see pull requests from time to time as I become familiar with covjson and the project code