Implements dataloading

PkmnLib.Tests/Dataloader/GrowthRateDataLoaderTests.cs

@@ -0,0 +1,14 @@
+using PkmnLib.Dataloader;
+
+namespace PkmnLib.Tests.Dataloader;
+
+public class GrowthRateDataLoaderTests
+{
+    [Test]
+    public void TestPrimaryGrowthRateFile()
+    {
+        using var file = File.Open("Data/GrowthRates.json", FileMode.Open);
+        var library = GrowthRateDataLoader.LoadGrowthRates(file);
+        Assert.That(library, Is.Not.Null);
+    }
+}