Update Marlin configuration with higher-resolution microstepping

[theacodes]

Our present Marlin configuration uses a very low resolution microstepping setting. The community has tested increasing these to the maximum of 256 steps for the X & Y axis without any drawbacks which allows consistent sub-millimeter movement.

This requires an update to the Marlin configuration repository, so no action is needed in this repository.

[jonnerd154]

The recent update to the Marlin configs was recently merged in (thank you @theacodes!) and it does provide a significant improvement to the machine's precision. The new values are a bit aggressive, and leave some room for improvement: 256-increment microstepping is more than needed for 0.01mm control precision, and puts a huge load on the controller for no benefit. Additionally the config does not allow for 0.01mm jogs to be carried out.

After experimentation I would like to propose a new configuration for four parameters. These parameters minimize microstepping while ensuring the machine will carry out any commands to 0.01mm, every time.

Configuration.h:

• DEFAULT_AXIS_STEPS_PER_UNIT --> { 160, 160, 40, 4.44, 4.44, 40 }
• MIN_STEPS_PER_SEGMENT --> 1

Configuration_adv.h:

• X_MICROSTEPS: 32
• Y_MICROSTEPS: 32