Add 'Blank' HTML, CSS, and JS Files

[HenriScaff]

Add the frontend "skeleton":

• HTML pages for our four views
• CSS page (can make separate ones later if necessary)
• JS script (placeholder, will likely need multiple)

Ensure the files interact properly using some basic tests (e.g. set background-color of the pages in CSS file, and have it changed by the JS).

This can lay the foundation for our first deliverable.