update unauthorized hub errors to include instructions

[dtam]

import guardrails as gr

from guardrails.hub import DetectPII

guard = gr.Guard()
guard.use_many(DetectPII(pii_entities=['PERSON', 'LOCATION']))

completion = guard(
    messages=[
        {
            "role": "user",
            "content": "Tell me about a city in california."
        }
    ],
    model="gpt-4o-mini"
)

print(completion)

should yield

Exception: 401: Remote Inference Unauthorized. Please run `guardrails configure`. You can find a new token at https://hub.guardrailsai.com/keys

and

guardrails hub install hub://guardrails/profanity_free

returns

Installing hub://guardrails/profanity_free...
401
Unauthorized
Your token is invalid. Please run `guardrails configure`to update your token.
You can find a new token at https://hub.guardrailsai.com/keys