Update simple.py link to a resource

[biscuitdelicious]

Hello,

There is a link in simple.py on line 20(https://www.algolia.com/doc/api-client/getting-started/instantiate-client-index/#initialize-an-index) that doesn't work anymore.

It gives me a 404 webpage when I access that link.

Could you please update the link with an up-to-date one?

Thanks!