add map of member repositories to web page

[mbjones]

Add a map of all repositories to the site. This can be done as a simple leaflet map importing data from the DataONE node capabilities service. @datadavev created a conversion utility that converts node info to geojson and posts it here:

https://raw.githubusercontent.com/datadavev/mnstatus/refs/heads/main/data/nodes.geojson

This can be easily mapped in leaflet, cesium, and other frameworks.

If the map is done in Cesium, it can be added to a custom portal page in markdown. We'd need to determine how to embed it via leaflet.

[datadavev]

Added a quick vanilla js leaflet view, should be easy to reuse pieces as needed:

• source: https://github.com/datadavev/mnstatus/blob/main/docs/index.html
• live: https://datadavev.github.io/mnstatus/

And a similar page using CesiumJS (thrown together with some Gemini assistance):

• source: https://github.com/datadavev/mnstatus/blob/main/docs/index_cesium.html
• live: https://datadavev.github.io/mnstatus/index_cesium.html