toJson method
Converts this ThemingConfig instance to a JSON map.
This method serializes the ThemingConfig object into a JSON representation that can be easily stored or transmitted.
Returns a Map containing the 'primaryColor', 'secondaryColor', and 'fontFamily' keys and their corresponding values.
Implementation
Map<String, dynamic> toJson() => {
'primaryColor': primaryColor,
'secondaryColor': secondaryColor,
'fontFamily': fontFamily,
};