Readme update for hooks

[jferragut]

Need to update the readme.md to reflect the changes in the most recent pull request.

• Context.Provider and Context.Consumer have been destructured for ease of use and are now imported as Provider and Consumer
• All Components were changed to Functions to support the use of hooks
• Actions and store work the same, but we changed the way appContext.js works
  • instead of class component, we are using function
  • constructor and state replaced by useState() hook
  • componentDidMount() was replaced by useEffect({},[]) which will only run at mount thanks to the second parameter

[jferragut]

@alesanchezr since we are going into Hacktoberfest, we can tag the repo for this boilerplate and also label this issue as a good first issue.

[timrodz]

Hey! Happy to take this on 😊