Add O1 model.

[thsunkid]

Noticed that we haven't supported o1, which leads to the issue such as this #326 if someone set the model name to o1 family models.

Can I send a PR to add O1?

[ghzeni]

Hey! First time commenter here 😄

@thsunkid please do! I'd love to see how we would go about maintaining this incredible plugin!! I'd be the first one to approve it even though it doesn't mean anything because I'm not a code owner 😬