[Keyboard] Add the Octopad (#9946)

* Create Alter folder

* Revert "Create Alter folder"

This reverts commit 361103b821dbb22957b66cdedb0d11f996def71c.

* Add octopad folder

* Added a new keyboard, the Octopad

* Edited files based on requested changes

* Moved encoder code in keyboard level

* Updated the readme

* Corrected the rows and columns of encoders on config.h

* Changed the Vendor ID to D812 since the first one was already taken

* Added support for ast1109MLTRQ speakers

* Increased number of layers to 8 on VIA keymap

* Edited files based on comments

* Edited rules.mk as per comment

* Edited readme.md as per comment

keyboards/nightly_boards/octopad/rules.mk

@@ -0,0 +1,26 @@
+# MCU name
+MCU = atmega32u4
+
+# Bootloader selection
+BOOTLOADER = atmel-dfu
+
+# Build Options
+#   change yes to no to disable
+#
+BOOTMAGIC_ENABLE = lite       # Virtual DIP switch configuration
+MOUSEKEY_ENABLE = yes         # Mouse keys
+EXTRAKEY_ENABLE = yes         # Audio control and System control
+CONSOLE_ENABLE = no           # Console for debug
+COMMAND_ENABLE = no           # Commands for debug and configuration
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
+SLEEP_LED_ENABLE = no         # Breathing sleep LED during USB suspend
+# if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
+NKRO_ENABLE = no              # USB Nkey Rollover
+BACKLIGHT_ENABLE = no         # Enable keyboard backlight functionality
+RGBLIGHT_ENABLE = yes         # Enable keyboard RGB underglow
+BLUETOOTH_ENABLE = no         # Enable Bluetooth
+AUDIO_ENABLE = yes             # Audio output
+ENCODER_ENABLE = yes          # Enable Rotary Encoders
+
+# Added encoder Action
+SRC +=  encoder_action.c