Add community resources section to README (#1590)

* Add community resources section to README

Added a section for community resources and integrations related to 3DTilesRendererJS.

#1576 (comment)

* Add iTowns to community resources README

* Simplified community resources, one link + desc per item

per garrett feedback on PR thread. also added 3DBAG viewer

* Update README.md

Author: jo-chemla

README.md

@@ -69,6 +69,18 @@ See the [Three.js usage guide](./USAGE.md) or [Babylon.js usage guide](./src/bab
 
 ¹ Requires a [Google Tiles API Key](https://developers.google.com/maps/documentation/tile/3d-tiles) or [Cesium Ion API Key](https://cesium.com/platform/cesium-ion/)
 
+# Community Resources
+
+Here is a reference to existing 3DTilesRendererJS integrations:
+
+- [three-geospatial](https://github.com/takram-design-engineering/three-geospatial): Clouds and atmosphere rendering via a three.js geospatial rendering modules, alongside 3DTilesRendererJS.
+- [3D Tiles in MapLibre Guide](https://maplibre.org/maplibre-gl-js/docs/examples/add-3d-tiles-using-threejs/): Official example showing how to render 3D tiles using a synced Three.js layer.
+- [Giro3D](https://gitlab.com/giro3d/giro3d): Framework for visualizing and interacting with heterogenous geospatial data in the browser, 2D, 2.5D and 3D data.
+- [iTowns](https://github.com/iTowns/itowns/): Framework designed for the efficient visualization, navigation, and interaction with 2D and 3D geospatial data on the web.
+- [threepipe Plugin](https://threepipe.org/package/plugin-3d-tiles-renderer.html): Plugin for the threepipe rendering framework integrating 3DTilesRendererJS.
+- [3DBAG Viewer](https://github.com/3DBAG/3dbag-viewer): Web viewer for the 3DBAG dataset, a nationwide 3D model of all buildings in the Netherlands built with roofer.
+- [Community Plugins](https://github.com/NASA-AMMOS/3DTilesRendererJS/tree/master/src/three/plugins#community-plugins): Additional community-maintained threejs plugins for 3DTilesRendererJS.
+
 # LICENSE
 
 The software is available under the [Apache V2.0 license](LICENSE).