config: Add a "printer-" prefix to example printer config files

Add a prefix to the example printer config files so that a sorted
directory listing shows all the samples bundled together.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/printer-wanhao-duplicator-i3-plus-2017.cfg

@@ -0,0 +1,78 @@
+# This file contains pin mappings for the Wanhao Duplicator i3 Plus
+# (circa 2017).  To use this config, the firmware should be compiled
+# for the AVR atmega2560.
+# Pin numbers and other parameters were extracted from the
+# official Marlin source available at:
+# https://github.com/garychen99/Duplicator-i3-plus
+
+# See the example.cfg file for a description of available parameters.
+
+[stepper_x]
+step_pin: PF7
+dir_pin: !PK0
+enable_pin: !PF6
+step_distance: .0125
+endstop_pin: ^!PF0
+position_endstop: 0
+position_max: 200
+homing_speed: 30.0
+
+[stepper_y]
+step_pin: PK2
+dir_pin: !PK3
+enable_pin: !PK1
+step_distance: .0125
+endstop_pin: ^!PA2
+position_endstop: 0
+position_max: 200
+homing_speed: 30.0
+
+[stepper_z]
+step_pin: PK5
+dir_pin: PK7
+enable_pin: !PK4
+step_distance: 0.0025
+endstop_pin: ^!PA1
+position_endstop: 0.5
+position_max: 180
+
+[extruder]
+step_pin: PF4
+dir_pin: PF5
+enable_pin: !PF3
+step_distance: 0.010417
+nozzle_diameter: 0.400
+filament_diameter: 1.750
+heater_pin: PG5
+sensor_type: EPCOS 100K B57560G104F
+sensor_pin: PF1
+control: pid
+pid_Kp: 30.850721
+pid_Ki: .208175
+pid_Kd: 192.298728
+min_temp: 0
+max_temp: 260
+
+[heater_bed]
+heater_pin: PE5
+sensor_type: EPCOS 100K B57560G104F
+sensor_pin: PK6
+control: pid
+pid_Kp: 64.095903
+pid_Ki: 1.649830
+pid_Kd: 622.531455
+min_temp: 0
+max_temp: 110
+
+[fan]
+pin: PE3
+
+[mcu]
+serial: /dev/ttyUSB0
+
+[printer]
+kinematics: cartesian
+max_velocity: 300
+max_accel: 800
+max_z_velocity: 5
+max_z_accel: 100