Move user config... somewhere

[jberstler]

One option is to move it to a separate JSON file like:

common: {
  username: 'TESLA_USERNAME',
  ...
},
start_climate: {
  min_battery_level: 20,
  ...
}
...

Another option is to force all the user config to come in from command line arguments, so that nobody has to edit files in order to specify these things.