Add SwiftUI demo project (#118)

* Commit after creating the project

* Add sherpa-onnx related files

* copy and modify files from sherpa-ncnn

* add app icon

ios-swiftui/SherpaOnnx/SherpaOnnxTests/SherpaOnnxTests.swift

@@ -0,0 +1,36 @@
+//
+//  SherpaOnnxTests.swift
+//  SherpaOnnxTests
+//
+//  Created by fangjun on 2023/4/5.
+//
+
+import XCTest
+@testable import SherpaOnnx
+
+final class SherpaOnnxTests: XCTestCase {
+
+    override func setUpWithError() throws {
+        // Put setup code here. This method is called before the invocation of each test method in the class.
+    }
+
+    override func tearDownWithError() throws {
+        // Put teardown code here. This method is called after the invocation of each test method in the class.
+    }
+
+    func testExample() throws {
+        // This is an example of a functional test case.
+        // Use XCTAssert and related functions to verify your tests produce the correct results.
+        // Any test you write for XCTest can be annotated as throws and async.
+        // Mark your test throws to produce an unexpected failure when your test encounters an uncaught error.
+        // Mark your test async to allow awaiting for asynchronous code to complete. Check the results with assertions afterwards.
+    }
+
+    func testPerformanceExample() throws {
+        // This is an example of a performance test case.
+        self.measure {
+            // Put the code you want to measure the time of here.
+        }
+    }
+
+}