Update BitcoinDevKit.swift and Package.swift for release 0.25.0

Package.swift

@@ -0,0 +1,36 @@
+// swift-tools-version:5.5
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "bdk-swift",
+    platforms: [
+        .macOS(.v12),
+        .iOS(.v15)
+    ],
+    products: [
+        // Products define the executables and libraries a package produces, and make them visible to other packages.
+        .library(
+            name: "BitcoinDevKit",
+            targets: ["bdkFFI", "BitcoinDevKit"]),
+    ],
+    dependencies: [
+        // Dependencies declare other packages that this package depends on.
+        // .package(url: /* package url */, from: "1.0.0"),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages this package depends on.
+        .binaryTarget(
+            name: "bdkFFI",
+            url: "https://github.com/bitcoindevkit/bdk-swift/releases/download/0.25.0/bdkFFI.xcframework.zip",
+            checksum: "4b9b4ebfc5c3d5d63eb62dd86a442f430262195cb247b0a402f522b25eff6708"),
+        .target(
+            name: "BitcoinDevKit",
+            dependencies: ["bdkFFI"]),
+        .testTarget(
+            name: "BitcoinDevKitTests",
+            dependencies: ["BitcoinDevKit"]),
+    ]
+)