Update for PDFTron iOS 8.1.2

Author: JamieDass

Package.swift

@@ -13,10 +13,12 @@ let package = Package(
         .binaryTarget(
             name: "PDFTron",
             url: "https://www.pdftron.com/downloads/ios/package/8.1.2/PDFTron.xcframework.zip",
-            checksum: ""),
+            checksum: "55b3f1f21ee5d9c9729bef8f69fde1d97bd14f407edb55b5f3e79c17ddd771b1
+"),
         .binaryTarget(
             name: "PDFTronTools",
             url: "https://www.pdftron.com/downloads/ios/package/8.1.2/PDFTronTools.xcframework.zip",
-            checksum: ""),
+            checksum: "f8b90ea9ac8888a512863154c4d6173e5c9001cf79631bf878b750380391cddb
+"),
     ]
 )