Move ckeys workshop to its own directory (#2928)

* move obelus and nakey to ckeys directory

* delete the originals

* short readme about ckeys

* edit readmes to reflect new changes

* add build guide info..and here's me trying to retrigger the build job

keyboards/ckeys/obelus/obelus.c

@@ -0,0 +1,28 @@
+#include "obelus.h"
+
+void matrix_init_kb(void) {
+	// put your keyboard start-up code here
+	// runs once when the firmware starts up
+	// Turn status LED on
+	DDRD |= (1<<6);
+	PORTD |= (1<<6);
+
+	matrix_init_user();
+}
+
+void matrix_scan_kb(void) {
+	// put your looping keyboard code here
+	// runs every cycle (a lot)
+	matrix_scan_user();
+}
+
+bool process_record_kb(uint16_t keycode, keyrecord_t *record) {
+	// put your per-action keyboard code here
+	// runs for every action, just before processing by the firmware
+	return process_record_user(keycode, record);
+}
+
+void led_set_kb(uint8_t usb_led) {
+	// put your keyboard LED indicator (ex: Caps Lock LED) toggling code here
+	led_set_user(usb_led);
+}