Add suport for A1111's metadata panels for models

A1111 recently added metadata panels for models, and their info is stored in a JSON file. If you have a lot of models, it can take a seriously long time to update these manually. It would be really handy if there was a way to autofill these (similar to CIVITAI Helper's info files), or even just download them prefilled with the models on the model page as an extra file (like suggested VAEs or configs).

Personally, the useful info would be the URL to the model page, usage tips, and the model description (About this version).