Update README.md

Author: shaoanlu

README.md

@@ -33,7 +33,8 @@ The policy takes 1) the latest N step of observation $o_t$ (position and velocit
 
 ### Deviation from the original implementation
 - Add a linear layer before the Mish activation to the condition encoder of `ConditionalResidualBlock1D`. This is to prevent the activation from truncating large negative values from the normalized observation.
-- A CLF-CBF-QP controller is implemented and used to modify the noisy actions during the denoising process of the policy. By default, this controller is not used.
+- A CLF-CBF-QP controller is implemented and used to modify the noisy actions during the denoising process of the policy. By default, this controller is disabled.
+- A finetuned model for single-step inference, which was trained following paper [Fine-Tuning Image-Conditional Diffusion Models is Easier than You Think](https://arxiv.org/abs/2409.11355), is used by default.
 
 <img src="assets/df_clf_cbf_comp.jpg" alt="drawing" width="600"/>