The file type is ".hex" when downloading code file from tutorial

[Helen09]

Repro steps:
• Navigate to https://makecode.chibitronics.com/#editor
• Click "Lights" -> right click on block "set" -> scroll down the help tutorial -> download the example code
• Click "Home" to back to home page
• Click "Import" to import the example code

Expected result:
The example code can be imported successfully
Actual result:
The example code can't be imported and it is ".hex" file

[Helen09]

The project file type downloaded from the editor page is .mkcd