Update REST API docs (currently outdated)

Some features which are implemented into the CivitAI REST API are undocumented on the docs.

For example, I've found that the following endpoint accepts query's that aren't listed:

https://civitai.com/api/v1/models

• `ids` Accepts a specific model ID.
  The API will return information on the specified model ID.
  (can be an array by repeating the parameter)

• `baseModels` Accepts a specific base model version.
  The API will return models containing the specified base model version.
  (can also be an array by repeating the parameter)

Currently, it's challenging to discern the API's full capabilities, especially given the limited responses to inquiries on the GitHub and here on featurebase.