Attempt to distinguish between settings on Windows and OSX.

- On Windows: using the dark theme with Source Code Pro Light font.
- On OSX: using the light theme with Ubuntu Mono font.
Tweaked the background color and font for Windows.

- Background set to light
- Font set to Source Code Pro Medium, size 20.
- The above setup plays nice when switching between light and dark backgrounds.
Changed the default fonts for Windows and OSX

- Windows font changed to Consolas:h14
- OSX font changed to Menlo:h12

Turns out that the default fonts are the ones that work better across monitors
with different resolutions and pixel density. Or even between different IDEs
since it isn't that uncommon for them to use their own font rendering
algorithms.