Move webapi to sub folder

GerbilManagerWebAPI/Dtos/UpdateLitterDto.cs

@@ -0,0 +1,12 @@
+
+namespace GerbilManager.Dtos
+{
+    public record UpdateLitterDto
+    {
+        public string Name { get; init; }
+        public DateTime Date { get; init; }
+        public int Strength { get; init; }
+        public Guid Father { get; init; }
+        public Guid Mother { get; init; }
+    }
+}