docs: update Changelog, README with pagination relation changes

Author: Yuri Zmytrakov

CHANGELOG.md

@@ -16,6 +16,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Fixed
 
+- Added missing relations in pagination for collections/{collection_id}/items, /search, /collections/{collection_id}/items, /collections. [[#432](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/432)]
+
 ## [v6.2.1] - 2025-09-02
 
 ### Added

README.md

@@ -376,7 +376,9 @@ The system uses a precise naming convention:
 - **Parameters**:
   - `limit`: Controls the number of collections returned per page
   - `token`: Used to retrieve subsequent pages of results
-- **Response Structure**: The `links` field in the response contains a `next` link with the token for the next page of results.
+- **Response Structure**: The `links` field in the response contains the following relations:
+  - `next` link with token for the next page of results.
+  - `previous` link with token for the previous page of results.
 - **Example Usage**:
   ```shell
   curl -X "GET" "http://localhost:8080/collections?limit=1&token=example_token"