add hook examples in README.md

[Vitormdias]

Would be nice to update the README, talk about hooks show some examples, and maybe show the updateState high order function notation

[filipeversehgi]

There is already a UseStream Hook Example inside the Readme:

const TestComponent = ({ name, total }) => { const state = useStream(state$) return ( <div> <h1 data-testid="name">{name}</h1> <p data-testid="total">Total: {total}</p> <p data-testid="changed">The store was{changed ? '' : n't} changed.</p> </div> ) }

But we lack HOC examples. I will try to add it soon.