Change the theme of our documentation website

[An3Dev]

I don't really like the light theme of the website, I'd like to make it have a dark theme and maybe even have Pacifica colors. We can do this by changing the stylesheet.css file in the gh-pages branch.

A problem I foresee is that every time we push changes to the main branch, the javadoc deploy action will run and will regenerate the documentation, which I think will overwrite the stylesheet.css. Maybe we can do something that'll lock the stylesheet.css file state so it doesn't get overwritten.

[flynneva]

@An3Dev this is a great idea, you should be able to set it up to use a logo I bet as well if you want to use one from Pacifica