🎨 use yaml to save config for training instead of Python File.

Both YAML and JSON are commonly used for storing configuration files, and both have their pros and cons.

Advantages of using YAML:
- YAML is often considered more readable and easier to write than JSON, as it uses a more compact and human-friendly syntax.
- YAML supports complex data structures, such as nested lists and dictionaries, and it can also handle more types of data, such as dates and times, than JSON.

Advantages of using JSON:
- JSON is a more widely used format than YAML, so it is supported by a larger number of tools and applications.
- JSON is a strict format, so it is less prone to syntax errors and unexpected behavior than YAML.
- Ultimately, the choice between YAML and JSON will depend on the specific requirements of your project, and what format is more suitable for your use case.

---

According to the answer of ChatGPY, we plan to use `yaml` for saveing configuration insead of `json`.