[Keyboard] Adding AEK64 keyboard (#6725)

* Adding AEK64 keyboard

* Deleting useless layout definition

* Resolving many code review issues

* Documenting my 4sStylZ keymap

* Adding default keymap

* Apply suggestions from code review

Code review corrections

Co-Authored-By: noroadsleft <18669334+noroadsleft@users.noreply.github.com>
Co-Authored-By: fauxpark <fauxpark@gmail.com>

* Update keyboards/handwired/aek64/readme.md

Co-Authored-By: noroadsleft <18669334+noroadsleft@users.noreply.github.com>

* Correcting the NKRO implementation

keyboards/handwired/aek64/aek64.c

@@ -0,0 +1,36 @@
+/*
+Copyright 2012,2013 Jun Wako <wakojun@gmail.com> <4sStylZ@protonmail.ch>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "quantum.h"
+
+/*
+ * Hardware function pre initialisation.
+ * See https://docs.qmk.fm/#/custom_quantum_functions?id=example-keyboard_pre_init_user-implementation
+ */
+void keyboard_pre_init_user(void) {
+  // Call the keyboard pre init code.
+
+  // Set our LED pins as output
+  setPinOutput(C3);
+}
+
+void matrix_init_kb(void) {
+
+    // Flash the led 1 sec on startup.
+    writePinHigh(C3);
+    wait_ms(1000);
+    writePinLow(C3);
+}