The base class [PretrainedConfig] implements the common methods for loading/saving a configuration
either from a local file or directory, or from a pretrained model configuration provided by the library (downloaded
from HuggingFace's AWS S3 repository).
Each derived config class implements model specific attributes. Common attributes present in all config classes are:
hidden_size, num_attention_heads, and num_hidden_layers. Text models further implement:
vocab_size.
PretrainedConfig
[[autodoc]] PretrainedConfig
    - push_to_hub
    - all
