[suggestions] improve docs and info

[bhirmbani]

Hi, what do you think about improve the docs. I recently have issue when DemoComponent which is showed up in the docs didn't use properly.

It should be imported at the top level component in the application, so when the user dispatch the action as suggested at the next step of the docs, it will show the DemoComponent.

The docs should also info that the notifications props cannot be renamed, otherwise it will turn error.