[E2B-402] Improve SDK error message when API key is missing

[mlejva]

This is the current message

throw new AuthenticationError('API key is required, please visit https://e2b.dev/docs to get your API key');
AuthenticationError: API key is required, please visit https://e2b.dev/docs to get your API key

We should mention that users can either pass the API key or set an environment variable. This is how OpenAI does it when you don't specify the API key

in JS SDK:

throw new Error("The OPENAI_API_KEY environment variable is missing or empty; either provide it, or instantiate the OpenAI client with an apiKey option, like new OpenAI({ apiKey: 'my apiKey' }).");
                  ^

Error: The OPENAI_API_KEY environment variable is missing or empty; either provide it, or instantiate the OpenAI client with an apiKey option, like new OpenAI({ apiKey: 'my apiKey' }).

in Python SDK:

No API key provided. You can set your API key in code using 'openai.api_key = <API-KEY>', or you can set the environment variable OPENAI_API_KEY=<API-KEY>). If your API key is stored in a file, you can point the openai module at it with 'openai.api_key_path = <PATH>'. You can generate API keys in the OpenAI web interface. See https://platform.openai.com/account/api-keys for details.

_{From SyncLinear.com | E2B-402}

[jakubno]

Solved by #293