Created the night stylesheet.
Revert "Created the night stylesheet."

This reverts commit 1ba90d38ad5372ccd40510528ec07614de815e2f.
Added night stylesheet!
Changed $dark-grey to $color—lighter-grey.
Change $heading-text-color to $color--darkest-grey
Change $main-text-color to $color--dark-grey
Change $secondary-text-color to $color--light-grey
Change $light-grey to $color--lightest-grey
Changed background to $color--background

Extrapolated the background color into a variable to that I can change it to a dark color in the night stylesheet.
Added JS night mode function and night settings.
Changed night stylesheet colors.
Changed short hr color.
Finished changes gridform night colors.
Merge branch 'feature/dark' into develop
Uncommented night mode script.