v1.16: Multimodal search

[guimachiavelli]

Fixes #3298

[dureuill]

It looks like the PR additionally makes changes related to code samples but unrelated to multimodal per se.

I didn't review these changes, only the multimodal ones.

The documentation looks right, I wonder if we should plan a more principled guide on how to setup a multimodal embedder with Voyage as backend 🤔

[guimachiavelli]

I should have mentioned that you needed not mind the code sample changes. They're a kink we haven't been able to iron out yet in our Mintlify workflow. Apologies for that, but, yes, I expected you to ignore them.

Regarding the guide, yes, that is something I think is necessary, but with everything happening internally I wasn't able to make the time for it before the release. 😢

[Strift]

Since we have an existing Voyage AI guide, maybe a quick win would be adding a "Multi-modal embeddings" section there? It could simply pull from the release notes example implementation?