Moved BindingGenerator from gen html project. It makes more sense here.

Sources/BindingGenerator/Internal/AppError.swift

@@ -0,0 +1,31 @@
+//
+//  AppError.swift
+//  HRW
+//
+//  Created by Isaac Paul on 10/13/24.
+//  Non-commercial license, see LICENSE.MD in the project root for details
+//
+
+import Foundation
+
+final class AppError: LocalizedError, Sendable {
+    
+    let message: String
+    
+    init(_ message: String) {
+        self.message = message
+    }
+    init(_ message: String, _ error:Error) {
+        self.message = "\(message) : \(error.localizedDescription)"
+    }
+    
+    static func failure<T>(_ message: String) -> Result<T, AppError> {
+        return .failure(AppError(message))
+    }
+    
+    var errorDescription: String? {
+        get {
+            return message
+        }
+    }
+}