Add mytyping.py to support and update transfer.py.

support/mytyping.py

+try:
+    from typing import NoReturn
+except (ImportError, NameError):
+    NoReturn = None

transfer.py

@@ -36,6 +36,8 @@ else:
     shutil.rmtree(os.path.join(disk, 'src'), True)
     shutil.rmtree(os.path.join(disk, 'boot_out.txt'), True)
     shutil.rmtree(os.path.join('src', '__pycache__'), True)
+    shutil.rmtree(os.path.join('support', '__pycache__'), True)
     shutil.copytree('src', os.path.join(disk, 'src'), dirs_exist_ok=True)
+    shutil.copytree('support', os.path.join(disk, 'support'), dirs_exist_ok=True)
     shutil.copy('code.py', os.path.join(disk, 'code.py'))
     print("Done! Switch back to the Serial Monitor!")