Add Square Nautical Mile to Area Units. (#677)

Author: angusguild

Common/UnitDefinitions/Area.json

@@ -234,6 +234,18 @@
           "Abbreviations": [ "ha" ]
         }
       ]
+    },
+    {
+      "SingularName": "SquareNauticalMile",
+      "PluralName": "SquareNauticalMiles",
+      "FromUnitToBaseFunc": "x*3429904",
+      "FromBaseToUnitFunc": "x/3429904",
+      "Localization": [
+        {
+          "Culture": "en-US",
+          "Abbreviations": ["nmi²"]
+        }
+      ]
     }
   ]
-}
+}

UnitsNet.Tests/CustomCode/AreaTests.cs

@@ -35,6 +35,8 @@ public class AreaTests : AreaTestsBase
 
         protected override double UsSurveySquareFeetInOneSquareMeter => 10.76386736111121;
 
+        protected override double SquareNauticalMilesInOneSquareMeter => 0.00000029155335;
+
         [Fact]
         public void AreaDividedByLengthEqualsLength()
         {