Add Dots Param to showString()
- Added dots parameter to showString() and showString_P() functions.
// void showString(const char s[], uint8_t length = MAXDIGITS, uint8_t pos = 0, uint8_t dots = 0);
display.showString("HHSS",4,0,0b01000000); // Expect: HH:SS or HH.SS
display.showString("1234",4,0,0b01000000); // Expect: 12:34 or 12.34