Missing baseurl parameters in some module configs

[databyjp]

Hi, while adding docs for the runtime (header-based) parameters, I noticed some that aren't currently in the client config factory functions:

X-Anyscale-Baseurl - needs baseurl in generative module
X-Voyageai-Baseurl - needs baseurl in reranker module
X-Mistral-Baseurl - needs baseurl in embedding & generative modules