v0.2.0

Changelog

• Added "empty_message" option to text box and pickers.
• Added "default" option to check box and text box
• Fixed errors when failing to read json files
• Made "button" key optional
• Modified window size for macOS
• Removed null values from gui_config.json
• Removed dependencies from macOS build

The released executables only work on 64-bit systems.
And the Linux build only works on Ubuntu 20.04 or later.