feat/refactor: Update Chimp Popup

[syoo881]

Updated Chimp game popup to include the current score, and look more appealing. Also rearranged the files within backend directory, to ensure that the backend directory is spelt "backend", not "Backend"

Context

Closes #84

What Changed?

• Updated ChimpTest popup, by changing the styling in ChimpTest.css, and addding a score counter within the ChimpTest.js
• Also, renamed the Backend folder to be "backend", not "Backend" to provide consistency across naming in the folders and files.

How To Review

• Take a look at the ChimpTest.css and ChimpTest.js to make sure everything else other than the intended popup is changed.
• Try to run the ChimpTest, and see if the popup shows as intended. Make sure that the backend information correctly updates.
• Double check if the backend folder is named "backend" with a lowercase b

Testing

• Tried playing multiple rounds of the ChimpTest, alongside submitting backend information.
  From my end, everything worked as intended.

Risks

• There is a chance that the popup may have changed information that is to be submitted to the backend. However, I don't believe this is the case, and I did not change anything in terms of objects to be submitted.

Notes

N/A

[jkim906]

Looks Good to me. thanks for the refactor and feature of the pop up. The pop up looks nicer now and looks ready to merge onto the main branch