Allow configuring `cc[VMIN]` and `cc[VTIME]`

[Nabav]

Currently, there are fixed configurations.

            settings.cc[VMIN] = 1;
            settings.cc[VSTOP] = 0x13; // XOFF
            settings.cc[VSTART] = 0x11; // XON
            settings.cc[VTIME] = 0;

In one application, this resulted to blocking read, since there were no time out and one byte was expected. So I have changed to

            settings.cc[VMIN] = 0;
            settings.cc[VSTOP] = 0x13; // XOFF
            settings.cc[VSTART] = 0x11; // XON
            settings.cc[VTIME] = 1;

and catched the error.EndOfStream after serial.reader().readByte().

This brings me to the point to request the ability to tweak these settings, if it is not yet there.

[ikskuh]

You can use this:
https://github.com/ziglang/zig/blob/master/lib/std/io.zig#L403C8-L407
for nonblocking i/o