UI Fixes & Dark Mode

[neonspectra]

This PR includes UI fixes as well as introduces a new dark mode (enabled by default). This is enough stuff that I might as well patch it up as a release to make it live.

• Dark Mode 😎
• Added a settings menu (replaces "About" menu) to include a toggle for dark mode as well as for whether to show background images.
• Reworked landing page styling to properly fit all elements as page shifts
• Cleaned up column wrapping to remove awkward spacing on mobile
• Fixed mojibake database entries for some flavour texts in various gear/traits.
• Fixed popup modals getting cut off and rendering off-screen on mobile