printUsage method
Prints the usage information for this command.
This is called internally by run and can be overridden by subclasses to control how output is displayed or integrate with a logging system.
Implementation
@override
void printUsage() {
print('Add Flutter packages to your project\n');
print('Usage:');
print(' dcf add <package1> [package2] [...]');
print(' dcf add --dev <package1> [package2] [...]');
print('\nOptions:');
print(' --dev Add as dev dependency');
print('\nExamples:');
print(' dcf add http');
print(' dcf add http dio shared_preferences');
print(' dcf add --dev build_runner');
}