update readme for collections w multi parents

Author: jonhealy1

README.md

@@ -28,7 +28,7 @@ The following organizations have contributed time and/or funding to support the
 
 ## Latest News
 
-- **12/09/2025:** Catalogs extension merged to main! The `/catalogs` endpoint is now available (optional via `ENABLE_CATALOGS_EXTENSION` environment variable) to enable federated hierarchical catalog browsing and navigation.
+- **12/09/2025:** Catalogs extension merged to main! The `/catalogs` endpoint is now available (optional via `ENABLE_CATALOGS_EXTENSION` environment variable) to enable federated hierarchical catalog browsing and navigation. Collections can belong to multiple catalogs for flexible hierarchical organization.
 - **11/07/2025:** 🌍 The SFEOS STAC Viewer is now available at: https://healy-hyperspatial.github.io/sfeos-web. Use this site to examine your data and test your STAC API!
 - **10/24/2025:** Added `previous_token` pagination using Redis for efficient navigation. This feature allows users to navigate backwards through large result sets by storing pagination state in Redis. To use this feature, ensure Redis is configured (see [Redis for navigation](#redis-for-navigation)) and set `REDIS_ENABLE=true` in your environment.
 - **10/23/2025:** The `EXCLUDED_FROM_QUERYABLES` environment variable was added to exclude fields from the `queryables` endpoint. See [docs](#excluding-fields-from-queryables).
@@ -240,6 +240,7 @@ This implementation follows the [STAC API Catalogs Extension](https://github.com
 ### Features
 
 - **Hierarchical Navigation**: Browse catalogs and sub-catalogs in a parent-child relationship structure
+- **Multi-Catalog Collections**: Collections can belong to multiple catalogs simultaneously, enabling flexible organizational hierarchies
 - **Collection Discovery**: Access collections within specific catalog contexts
 - **STAC API Compliance**: Follows STAC specification for catalog objects and linking
 - **Flexible Querying**: Support for standard STAC API query parameters when browsing collections within catalogs