Start json reader

DotTiled.Tests/Serialization/Tmj/TmjMapReaderTests.cs

@@ -0,0 +1,32 @@
+namespace DotTiled.Tests;
+
+public partial class TmjMapReaderTests
+{
+  [Fact]
+  public void Test1()
+  {
+    // Arrange
+    var jsonString =
+    """
+    {
+      "backgroundcolor":"#656667",
+      "height":4,
+      "nextobjectid":1,
+      "nextlayerid":1,
+      "orientation":"orthogonal",
+      "renderorder":"right-down",
+      "tileheight":32,
+      "tilewidth":32,
+      "version":"1",
+      "tiledversion":"1.0.3",
+      "width":4
+    }
+    """;
+
+    // Act
+    using var tmjMapReader = new TmjMapReader(jsonString);
+
+    // Assert
+    var map = tmjMapReader.ReadMap();
+  }
+}