up-fs-hex: Change constructor arguments to make the hex file optional.

Author: microbit-carlos

LICENSE.md

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2019 Micro:bit Educational Foundation
+Copyright (c) 2019-2020 Micro:bit Educational Foundation
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

docs/quick-guide.md

@@ -13,8 +13,8 @@ Initialise a File System instance with a MicroPython Intel Hex string and start
 
 ```js
 // Create a new FileSystem instance passing the MicroPython Intel Hex string
-var micropythonFs = new microbitFs.MicropythonFsHex(IntelHexStr);
-var micropythonFsWithFiles = = new microbitFs.MicropythonFsHex(UploadedHexWithUserFiles);
+var micropythonFs = new microbitFs.MicropythonFsHex({ uPyHex: IntelHexStr });
+var micropythonFsWithRestrictedFsSize = new microbitFs.MicropythonFsHex({ uPyHex: IntelHexStr, maxFsSize: 20 * 1024 });
 
 // Import files from a different MicroPython hex file with filesystem
 var addedFilenames = micropythonFs.importFilesFromIntelHex(UploadedHexWithUserFiles);