Fix CohereError: embed is not an available endpoint on this model

[mmz-001]

Running the Cohere embeddings example from the docs:

from langchain.embeddings import CohereEmbeddings
embeddings = CohereEmbeddings(cohere_api_key= cohere_api_key)

text = "This is a test document."
query_result = embeddings.embed_query(text)
doc_result = embeddings.embed_documents([text])

I get the error:

CohereError(message=res['message'], http_status=response.status_code, headers=response.headers)      
cohere.error.CohereError: embed is not an available endpoint on this model

This is because the model string is set to medium which is not currently available.

From the Cohere docs:

Currently available models are small and large (default)

[hwchase17]

thank you!