Batch inference support (self-assigning)

[willccbb]

Would be nice to have batch inference support similar to mlx_parallm, happy to try and add soon. @Blaizzy can you assign this to me?

[Blaizzy]

Hey Will,

Yes, that would be awesome!

I have assigned the task to you 😀

[Blaizzy]

Please comment #40 here so I can assign it to you and discuss details on a single issue.