Keep the v1-inference.yaml file, to be able to load SD1 models

[cmdr2]

The SD 2.0 code is capable of loading the older models (SD 1.4), but needs the old v1 config file to load. This PR includes the earlier v1-inference.yaml config file, used for loading SD1.4 models.

It would be useful for people to be able have both versions in this project.

Being able to load the older models is useful, since many users try to recreate/fine-tune past images made with the 1.4/1.5 model (by using the same prompt+settings, that they used previously).

Thanks!

[cmdr2]

Not sure if the documentation label is accurate, because this contributes a config file required for loading SD 1.4 models?