Style the webpage

[gnattily]

Is your feature request related to a problem? Please describe.
The current UI is a disaster. It's barely even functional: end pieces all look the same, there's nothing to show you how many ships are in each row/column, and there's no indicator for ships left.

Describe the solution you'd like
A well though-out and cohesive UI should be created with options for theme, font, size, etc. It should be sure to keep accessibility in mind.

[gnattily]

A full overhaul would be too much work right now. Other elements such as generating boards (#20), detecting when it's solved (#25), etc. need to be completed before this.

For now, a smaller update to just make the game playable would be more apt.