Adjust dark mode colorscheme (#225)

* Adjust dark mode colorscheme

This makes the whites a bit softer and instead of
inverting the blue hyperlinks, they're now desaturated -
but still blue.

* Add Ariejan de Vroom to CONTRIBUTORS

CONTRIBUTORS.md

@@ -45,3 +45,4 @@
 - [Shreyansh Khajanchi](https://shreyanshja.in)
 - [Lionel Brianto](https://lionel.brianto.dev)
 - [Luis Zarate](https://github.com/jlzaratec)
+- [Ariejan de Vroom](https://www.devroom.io)

assets/scss/_variables.scss

@@ -12,7 +12,7 @@ $link-color: #1565c0 !default;
 
 // Colors inverted
 $bg-color-inverted: #212121 !default;
-$fg-color-inverted: #fafafa !default;
+$fg-color-inverted: #dadada !default;
 $alt-bg-color-inverted: #424242 !default;
-$alt-fg-color-inverted: #fafafa !default;
-$link-color-inverted: #f44336 !default;
+$alt-fg-color-inverted: #dadada !default;
+$link-color-inverted: #36679f !default;