add tutorial guide

Common/Data/Config/StringToUIntConverter.cs

@@ -0,0 +1,24 @@
+using Newtonsoft.Json;
+
+namespace MikuSB.Data.Config;
+
+public class StringToUIntConverter : JsonConverter<uint>
+{
+    public override uint ReadJson(JsonReader reader, Type objectType, uint existingValue, bool hasExistingValue, JsonSerializer serializer)
+    {
+        if (reader.Value == null)
+            return 0;
+
+        var value = reader.Value.ToString();
+
+        if (string.IsNullOrWhiteSpace(value))
+            return 0;
+
+        return uint.TryParse(value, out var result) ? result : 0;
+    }
+
+    public override void WriteJson(JsonWriter writer, uint value, JsonSerializer serializer)
+    {
+        writer.WriteValue(value);
+    }
+}