[FEATURE REQ] Support dark mode

[ssafayet]

Is your feature request related to a problem? Please describe.
Right now this project only shows the application in the light mode. Cool to have support for dark mode also.

Describe the solution you'd like
The user should be able to toggle between light/dark modes. By default, it will detect the system's theme settings and render accordingly. If the user chooses a theme other than the system settings, it should remember the selection.