add dark mode

[delasource]

Add a dark mode.

Or even better, css customizations via GET parameters. Like

https://hugovk.github.io/year-progress-bar/?background=000000&progressbar=cc7df6&font=cccccc&family=Arial

[hugovk]

Thanks for the suggestion, how does https://hugovk.github.io/year-progress-bar/ / b300cb3 look?