Add CodeSandbox examples for basic use cases

[bpas247]

CodeSandbox provides a way to deploy example project setups. Due to the way you can import specific paths for GitHub repositories, we should consider adding examples to a new subdirectory in this repository for these examples, as it will allow users to be able to bootstrap their ReactN projects.

[quisido]

I support this idea. But given I don't have a lot of experience with CodeSandbox, I'll probably prioritize finishing the documentation over this. I do welcome user-submitted CodeSandbox examples, though, and I'll leave this as a milestone for after the documentation is completed.

[pikilon]

I am trying to do examples but I get null from global state

I can't tell if is the codesandbox or the reactn

https://codesandbox.io/embed/testing-reactn-hooks-lc0ci

[quisido]

Thanks for your contributions!

It looks to me like it should be const [cards] = useGlobal('cards');

As is, you are returning the entire global state object instead of the array of cards.

[pikilon]

can you access nested state with this pattern or simillar?
const [id] = useGlobal('users.id');

I founded here, sorry
#4 (comment)