Made serialization of Command optional. If command is serialized, Control (On Win/Linux) or Meta (on Mac) are not.
Example use case: You are on Windows and you set a shortcut to be Control + E. This would serialize as Command=true and Control=true. If you then run this project on Mac, you would need to press Command AND Control to activate the shortcut - which is not what is intended. Now, you can set store_command to true, and it will only serialize to Command = true (no Control serialized). On Windows, this means Control. On Mac, it means only command.