Update Rationale.md

docs/machines/desktop_cnc/Rationale.md

@@ -75,13 +75,13 @@ The Y 8mm front and back plates seems too thin to properly hold the bearing and
 
 Add milled alignment for the bottom bearing support of the Z ball screw.
 
-Surface where the Z axis linear guides will sit.
-
-Surface where the carriages will sit.
-
 Fix X Motor footprint on shoulder. It should be +2mm on top/bottom.
 
 Radius of the Z Top bearing cap should be 13mm instead of 13.5
 
-Surface Y back bearing holder for perpendicularity with the bed supporting plate
+Surface the following:
+
+- Y back bearing holder for perpendicularity with the bed supporting plate
+- where the carriages will sit (every spots)
+- where the Z axis linear guides will sit.