Update CHANGELOG

Author: stellasia

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 
 - Added the `run_with_context` method to `Component`. This method includes a `context_` parameter, which provides information about the pipeline from which the component is executed (e.g., the `run_id`). It also enables the component to send events to the pipeline's callback function.
+- Exposed `schema_builder`, `chunk_embedder`, `extractor` and `resolver` in the `SimpleKGPipeline` constructor so that they can be customized.
 
 
 ## 1.6.0