services/printer library

1. elgin package
2. documentation
3. services/printer.dart

elgin package

1. Libraries
2. components/elgin.barcode_type
3. components/elgin_align
4. components/elgin_barcode_text_position
5. components/elgin_font
6. components/elgin_printer
7. components/elgin_printer_model
8. components/elgin_printer_type
9. components/elgin_qrcode_correction
10. components/elgin_qrcode_size
11. components/elgin_size
12. components/enums
13. components/exceptions/connection/elgin_errors
14. components/exceptions/elgin_exception
15. elgin
16. services/printer