REQ: Increase the ganged axis homing offset adjustment from +/- 2mm to +/- 10mm t support larger machines

[5ocworkshop]

I have a fairly large machine, my X is over 1100mm of travel. In going through detailed calibration after moving house and taking the machine apart, I discovered I needed to adjust my ganged Y axis homing offset to -5 mm to get back in to square. The firmware currently limits that value to +/- 2mm. It appears a lot of my error is derived from hand made sensor mount brackets.

It would be good to support a wider range of values, I suggest +/- 10.xxx mm for that variable to allow for errors that may exist in larger machines or and made machines/sensor brackets.

While there is the potential to rack the gantry if a high value is used here incorrectly, there are various ways a person can rack or damage a machine if they set incorrect values and this is largely a one-time calibration value that is not in the normal workflow so I can't think of any reason not to increase the allowable range.

https://github.com/grblHAL/core/blob/e3e74847311df5c772754b61d817c21f48b81dfb/settings.c#L508

 { Setting_AxisAutoSquareOffset, Group_Axis0, "?-axis dual axis offset", "mm", Format_Decimal, "-0.000", "-10", "10", Setting_IsExtendedFn, set_axis_setting, get_float, is_setting_available },

(Thanks to Andrew Marles for making me a quick build to test it).