Keyboards: Move the other Sentraq keyboards into the sentraq vendor directory (#5052)

* Moving sentraq keyboards to sentraq subdirectory.

* Updating readme markdown to correct make commands.

* Updating s60_x references to point to the new vendor subdirectory.

* Fixed stripped spaces in markdown.

* Updated help information in s60_x readme and linked to additional documentation.

keyboards/sentraq/s65_plus/s65_plus.c

@@ -0,0 +1,24 @@
+#include "s65_plus.h"
+#include "led.h"
+
+void matrix_init_kb(void) {
+  // put your keyboard start-up code here
+  // runs once when the firmware starts up
+  matrix_init_user();
+};
+
+void matrix_scan_kb(void) {
+  // put your looping keyboard code here
+  // runs every cycle (a lot)
+  matrix_scan_user();
+};
+
+void led_set_kb(uint8_t usb_led) {
+  if (usb_led & (1<<USB_LED_CAPS_LOCK)) {
+    // Turn capslock on
+    PORTB &= ~(1<<7);
+  } else {
+    // Turn capslock off
+    PORTB |= (1<<7);
+  }
+}