Update doc example

[shavidzet]

import habitat from 'preact-habitat';
import WidgetAwesome from './components/WidgetAwesome';

let habitat = habitat(WidgetAwesome);

habitat is already used while we import package and it would be better if we don't override variable. I think it needs to have different name like habitatTemplate or something else except habitat

[zouhir]

just merged a fix for this example! good catch! thank you!