Fix USAGE.md links

Fix `demo_part1.ipynb` and `demo_part2.ipynb` link

Author: SulthanAbiyyu

docs/USAGE.md

@@ -42,15 +42,15 @@ pip install -r requirements.txt
 Download the checkpoint from [here](https://myshell-public-repo-hosting.s3.amazonaws.com/checkpoints_1226.zip) and extract it to the `checkpoints` folder 
 
 **1. Flexible Voice Style Control.**
-Please see [`demo_part1.ipynb`](demo_part1.ipynb) for an example usage of how OpenVoice enables flexible style control over the cloned voice.
+Please see [`demo_part1.ipynb`](../demo_part1.ipynb) for an example usage of how OpenVoice enables flexible style control over the cloned voice.
 
 **2. Cross-Lingual Voice Cloning.**
-Please see [`demo_part2.ipynb`](demo_part2.ipynb) for an example for languages seen or unseen in the MSML training set.
+Please see [`demo_part2.ipynb`](../demo_part2.ipynb) for an example for languages seen or unseen in the MSML training set.
 
 **3. Gradio Demo.**. We provide a minimalist local gradio demo here. We strongly suggest the users to look into `demo_part1.ipynb`, `demo_part2.ipynb` and the [QnA](QA.md) if they run into issues with the gradio demo. Launch a local gradio demo with `python -m openvoice_app --share`.
 
 **3. Advanced Usage.**
 The base speaker model can be replaced with any model (in any language and style) that the user prefer. Please use the `se_extractor.get_se` function as demonstrated in the demo to extract the tone color embedding for the new base speaker.
 
 **4. Tips to Generate Natural Speech.**
-There are many single or multi-speaker TTS methods that can generate natural speech, and are readily available. By simply replacing the base speaker model with the model you prefer, you can push the speech naturalness to a level you desire.
+There are many single or multi-speaker TTS methods that can generate natural speech, and are readily available. By simply replacing the base speaker model with the model you prefer, you can push the speech naturalness to a level you desire.