chore: update changelog for 0.5.0

Signed-off-by: Oleg S <[email protected]>

Author: RobotSail

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.5.0
+
+* Introduces Ragas as a supported evaluation framework. This integration only supports the `RubricsScore` metric and OpenAI models. Users can pass in either a dataset with a pre-computed `user_input`, `reference` and `response` fields or they can provide a dataset containing `user_input` and `reference` along with information about a model endpoint that will be used for computing the `response` field.
+
 ## 0.4.2
 
 * Adds the ability to provide a custom system prompt to the MMLU-based evaluators. When a system prompt is provided, LM-eval applies the chat template under the hood, else it will pass the model a barebones prompt.