Changelog 5th December (#822)

* Updated changelog

apps/opik-documentation/documentation/docs/changelog.md

@@ -5,6 +5,21 @@ sidebar_label: Changelog
 
 # Weekly Changelog
 
+## Week of 2024-12-02
+
+**Opik Dashboard**:
+
+- Added a new `created_by` column for each table to indicate who created the record
+- Mask the API key in the user menu
+
+**SDK**:
+
+- Implement background batch sending of traces to speed up processing of trace creation requests
+- Updated OpenAI integration to track cost of LLM calls
+- Updated `prompt.format` method to raise an error when it is called with the wrong arguments
+- Updated the `Opik` method so it accepts the `api_key` parameter as a positional argument
+- Improved the prompt template for the `hallucination` metric
+
 ## Week of 2024-11-25
 
 **Opik Dashboard**: