Add some more models (nw)

SabreTools.Models/OpenMSX/SoftwareDb.cs

@@ -0,0 +1,15 @@
+using System.Xml;
+using System.Xml.Serialization;
+
+namespace SabreTools.Models.OpenMSX
+{
+    [XmlRoot("softwaredb")]
+    public class SoftwareDb
+    {
+        [XmlAttribute("timestamp")]
+        public string? Timestamp { get; set; }
+
+        [XmlAttribute("software")]
+        public Software[]? Software { get; set; }
+    }
+}