Base: Add Nord theme

Nord (specifically Polar Night) is a popular soft dark blue/grey theme.

Personally, I find it to be a very nice middle-ground between the contrast of the
dark and light (default) theme.

![Preview](https://i.imgur.com/6sVnT4i.png)

Base/res/themes/Nord.ini

@@ -0,0 +1,37 @@
+[Colors]
+DesktopBackground=#3b4252
+ActiveWindowBorder1=#4c566a
+ActiveWindowBorder2=#434c5e
+ActiveWindowTitle=white
+InactiveWindowBorder1=#2e3440
+InactiveWindowBorder2=#3b4252
+InactiveWindowTitle=white
+MovingWindowBorder1=#4c566a
+MovingWindowBorder2=#4c566a
+MovingWindowTitle=white
+HighlightWindowBorder1=#4c566a
+HighlightWindowBorder2=#4c566a
+HighlightWindowTitle=white
+MenuBase=#434c5e
+MenuBaseText=white
+MenuStripe=#4c566a
+MenuSelection=#4c566a
+MenuSelectionText=white
+Window=#2e3440
+WindowText=white
+Button=#434c5e
+ButtonText=white
+Base=#4c566a
+BaseText=white
+ThreedHighlight=#4c566a
+ThreedShadow1=#3b4252
+ThreedShadow2=#2e3440
+HoverHighlight=#7e9dbc
+Selection=#7e9dbc
+SelectionText=white
+RubberBandFill=#04434c5e
+RubberBandBorder=#4c566a
+Link=#7e9dbc
+ActiveLink=#95adc5
+VisitedLink=#3b4e68
+