Add hintStyle for empty display

[cezaryjk]

Hi,
Just to show zero for cleared display the same way as "regular" result I would suggest to use hintStyle:
Maybe like this:
decoration: InputDecoration(
border: InputBorder.none,
hintText: '0',
// CK
hintStyle: TextStyle(fontSize: 40.0),
// end CK
),

Maybe with use of variable for display fontSize?
What do you think?

BR
Cezary

[Gperez88]

thanks for your feedback, i will check to put on next version