feat: romaji plugin (without dict)

RomajiConverter.Core/Models/ReplaceString.cs

@@ -0,0 +1,23 @@
+namespace RomajiConverter.Core.Models
+{
+    public class ReplaceString
+    {
+        public ReplaceString(ushort id, string value, bool isSystem)
+        {
+            Id = id;
+            Value = value;
+            IsSystem = isSystem;
+        }
+
+        public ushort Id { get; set; }
+
+        public string Value { get; set; }
+
+        public bool IsSystem { get; set; }
+
+        public override string ToString()
+        {
+            return Value;
+        }
+    }
+}