SPM support (#7)

* Add SPM support

* downgrade swift-tools-version to 5.3

* remove whitespace after swift tools specifier

* fix loading `player.html` for SPM

Author: nklhtv

BeyondWordsPlayer/BeyondWordsPlayer/PlayerView.swift

@@ -34,9 +34,15 @@ public class PlayerView: UIView {
             webView.isInspectable = true
 #endif
         }
+#if SWIFT_PACKAGE
+        guard let playerHTMLPath = Bundle.module.path(forResource: "player", ofType: "html") else {
+            fatalError("player.html not found!")
+        }
+#else
         guard let playerHTMLPath = Bundle(for: PlayerView.self).path(forResource: "player", ofType: "html") else {
             fatalError("player.html not found!")
         }
+#endif
         guard let playerHTMLPage = try? String(contentsOfFile: playerHTMLPath) else {
             fatalError("player.html could not be loaded!")
         }

Package.swift

@@ -0,0 +1,25 @@
+// swift-tools-version:5.3
+
+import PackageDescription
+
+let package = Package(
+    name: "BeyondWordsPlayer",
+    platforms: [
+        .iOS(.v13)
+    ],
+    products: [
+        .library(
+            name: "BeyondWordsPlayer",
+            targets: ["BeyondWordsPlayer"]
+        )
+    ],
+    targets: [
+        .target(
+            name: "BeyondWordsPlayer",
+            path: "BeyondWordsPlayer/BeyondWordsPlayer",
+            resources: [
+                .process("player.html")
+            ]
+        )
+    ]
+)