Tool suggestion: Historical-Satellite and Terrain-Viewer from Iconem

Hi there,

First of all, thanks a lot for this great resource and the cconstant source for inspiration of your whole team and work. I just recently reworked on [terrain-viewer](https://terrain-viewer.iconem.com/), an app initially meant to quickly edit via maplibre some terrain layers symbology (hillshade, hypso, contours, basemap, useful for geoarchaeology), and added terrain analysis (slope, roughness, curvature, Terrain Ruggedness Index, Topographic Position Index), relief-visualization, and lighting (phong etc).

What's probably most important to bellingcat toolkit would rather be that I also extended it to allow comparing basemaps from esri-wayback, google-earth historical, lower resolution Harmonized Landsat Sentinel, EOX, and let user bring their own keys for eg Planet Labs monthly mosaics, or others. They can use overlay with blending modes, or an N-grid (eg 4x2) grid of synced map views at different point in time via timeline. A sun shadow position estimator tool offers forward/reverse modes to estimate datetime from shadow and known object height.

Here are the links, the docs is well architectured and well versed in screenshots.

What would be the process to get that tool into the toolkit?

- [beta.historical-satellite](https://beta.historical-satellite.iconem.com/)
- [docs for basemaps-and-historical](https://terrain-viewer.iconem.com/docs/features/basemaps-and-historical)
- [walkthrough tour](http://terrain-viewer.iconem.com/?startTour=true)

Note: the older app `historical-satellite.iconem.com` is being phased out to legacy, replaced by this `terrain-viewer appMode`, so `beta.historical-satellite.iconem.com` should at some point be replaced by just `historical-satellite.iconem.com`

Start by reviewing the linked beta.historical-satellite app, terrain-viewer documentation, and walkthrough tour. The issue names no repository files or tests; done would require a maintainer-approved scope and integration plan for bringing the external tools into the toolkit.

Written by the indexing model from the issue text.