Simple react app for a treasure hunt created for my friends.

This web app is deployed automatically on Heroku using this action and is available at king-treasure-hunt.herokuapp.com .

Not my best code, but I need something as fast as I can.

I decided to only run the app (and not build it) in the Dockerfile because I need to keep secret the keys to win, even if my friends come here to cheat; to obtain this in the fastest way possible without having to create a backend server to verify keys, I decided to store the keys in environment variables (that are not reachable from a built react app... or at least I wasn't able to).
Said variables are set directly on Heroku (or in the docker-compose file).

There are the environment variables to keep in mind while using this web app (all starting with REACT_APP due to React environment variables restrictions):

• REACT_APP_FIRST_KEY, REACT_APP_SECOND_KEY, REACT_APP_THIRD_KEY, REACT_APP_FOURTH_KEY:
  In the landing page there are 4 textboxes that corresponds to this four variables.
• REACT_APP_FINAL_KEY:
  Once the fist 4 keys are guessed, there will be another textbox to input the final key.
• REACT_APP_FINAL_PAGE_TEXT:
  Message for the winners.

There are also 3 additional variables used to set parameters to send an email when a step is completed. You don't need to specify them, the mail simply won't be sent.
If you want to send a mail, here is a tutorial of what you need to do.

• REACT_APP_EMAILJS_USER_CODE
• REACT_APP_MID_MAIL_TEMPLATE
• REACT_APP_FINAL_MAIL_TEMPLATE