Function create_embedding 

pub fn create_embedding<C, Fut, B, E>(
    client: C,
    request: &CreateEmbeddingRequest,
) -> CreateEmbedding<Fut, B, E> 
where
    C: FnOnce(Request<String>) -> Fut,
    Fut: Future<Output = Result<Response<B>, E>>,
    B: Body,

Create embeddings