added setup guide

documentation/setup_guide.md

@@ -0,0 +1,13 @@
+# Troubleshooting Common Problems
+
+## Checklist for New Devices
+
+1. **Was the mechanical limit pin added to the rotor?**  
+   This pin is required for proper homing of the device.
+
+2. **Are the screws that secure the rotor to the motor shaft installed?**  
+   If the rotor is not firmly attached, it may slip slightly during homing or other movements, which can lead to positioning errors.
+
+3. **Is the homing direction correct?**  
+   During the homing command (`G28`), the end effector should move toward the base.  
+   If it moves in the opposite direction, rewire the motor to reverse its direction.