Update my Quefrency/KBD67 keymaps, adding BDN9 macropad keymap as well (#5924)

* Set Quefrency bootloader correctly for Elite-C

* Update Quefrency layout to be more like HHKB

* Update KBD67 layout to be more like HHKB

* Add keymap for BDN9 macropad

keyboards/keebio/bdn9/keymaps/bcat/keymap.c

@@ -0,0 +1,43 @@
+#include QMK_KEYBOARD_H
+
+enum layer {
+    LAYER_FIRST,
+    LAYER_SECOND,
+};
+
+/* Switch to second layer when held. */
+#define LY_SECND MO(LAYER_SECOND)
+
+const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* First layer (F1-F6) */
+    [LAYER_FIRST] = LAYOUT(
+        KC_MUTE,  LY_SECND, BL_TOGG,  \
+        KC_F4,    KC_F5,    KC_F6,    \
+        KC_F1,    KC_F2,    KC_F3     \
+    ),
+
+    /* Second layer (F7-F12) */
+    [LAYER_SECOND] = LAYOUT(
+        _______,  _______,  _______,  \
+        KC_F10,   KC_F11,   KC_F12,   \
+        KC_F7,    KC_F8,    KC_F9     \
+    ),
+};
+
+void encoder_update_user(uint8_t index, bool clockwise) {
+    switch (index) {
+        /* Top-left encoder (volume): */
+        case 0:
+            tap_code(clockwise ? KC_VOLU : KC_VOLD);
+            break;
+    
+        /* Top-right encoder (backlight brightness): */
+        case 1:
+            if (clockwise) {
+                backlight_increase();
+            } else {
+                backlight_decrease();
+            }
+            break;
+    }
+}