Make remote setup code easy to find

[loftusa]

I had to find the below from this colab:

from nnsight import CONFIG

CONFIG.set_default_api_key("<your api key here>")

It may be on the website, but I couldn't find it quickly if it was. Should be front and center somewhere.
Side note, I think this setup in general should be changed - it incentivizes people putting in API keys in raw form, to code that has a high chance of getting thrown on github somewhere. Much better in my opinion would be using click or similar to add an nnsight login CLI command, similar to the huggingface login command.