[Feature Request] Support FromOriginalModelMixin(original_config=yaml)

[iwr-redmond]

This FR may replace issue 16 if my understanding of diffusers is correct. If the method proposed here is workable, then the earlier FR can be closed.

Although standard model loading no longer supports using YAML files containing the model generation parameters, such as those distributed via Civitai, the FromOriginalModelMixin class does:

original_config (str, optional) — Dict or path to a yaml file containing the configuration for the model in its original format. If a dict is provided, it will be used to initialize the model configuration.

Please consider adding support for YAML file loading into Model_Diffusers.