move mechkeys keyboards into the mechkeys/ vendor folder (#15760)

* move mechkeys keyboards to mechkeys/

* fix compilation

* fix default folder

keyboards/mechkeys/mechmini/v1/rules.mk

@@ -0,0 +1,17 @@
+# MCU name
+MCU = atmega32a
+
+# Bootloader selection
+BOOTLOADER = bootloadhid
+
+# Build Options
+#   change yes to no to disable
+#
+BOOTMAGIC_ENABLE = yes      # Enable Bootmagic Lite
+MOUSEKEY_ENABLE = yes
+EXTRAKEY_ENABLE = yes
+CONSOLE_ENABLE = no
+COMMAND_ENABLE = yes
+BACKLIGHT_ENABLE = yes
+RGBLIGHT_ENABLE = yes
+WS2812_DRIVER = i2c