[DOCS] move llm hyperparameter optimisation design image to the proposal directory and rename it (kubeflow#2472)

- remove redundant folder

Signed-off-by: mahdikhashan <[email protected]>
Signed-off-by: Gary Miguel <[email protected]>

Author: mahdikhashan

docs/proposals/2339-hpo-for-llm-fine-tuning/README.md

@@ -30,7 +30,7 @@ Our goal is to develop a high-level API for tuning hyperparameters of LLMs that
 
 ## Design for API
 
-![Design for API](images/design_api.jpg)
+![Design for API](hp-optimization-api-design.jpg)
 
 ```python
 import kubeflow.katib as katib