typo in docs: replace Non with None

[thsmale]

Code example for querystring_validation list values may want to be updated further.

For example, may want to import Optional from typing as well. Also, it was suggested to me to use list instead of List in class Query.

Also, is there a guide for testing changes to the docs locally? I only tried briefly but was unsuccessful in testing these changes locally.

[pgjones]

Thanks