Update 01 Hello React Readme

[brauliodiez]

Steps:

• Update Readme.md (and es) version
• Update code
• Check that code runs
• Go through readme ensure the sample can be build following readme steps.

Update A:

old version

import * as React from 'react';

export const HelloComponent = () => {
  return (
    <h2>Hello component !</h2>
  );
}

proposal

import * as React from 'react';

export const HelloComponent = () => 
    <h2>Hello component !</h2>