[Keyboard] PCB Ruler updates (#6584)

* Move default keymap's rules to keyboard level

* Concatenate the two sets of rules

This sets CONSOLE_ENABLE to no, which was being set at the keymap level.

* Wrap the USB Device Description in quotes

Some preventative maintenance. The firmware for the_ruler can't be compiled without this change if `CONSOLE_ENABLE = yes` because this string has a comma, which gets picked up as two arguments by the Command code, instead of one as it should be.

* Linting

- remove firmware size impacts
- remove trailing white space
- visual alignment of rules

* Use QMK's pre-loaded default rules for atmega32u4

* Update readme

- markdown formatting
- update Hardware Availability link (Maple Computing's site has disappeared)
- update Docs links

* Update header files to use #pragma once

keyboards/the_ruler/keymaps/default/rules.mk

@@ -1,18 +0,0 @@
-# Build Options
-#   change to "no" to disable the options, or define them in the Makefile in 
-#   the appropriate keymap folder that will get included automatically
-#
-BOOTMAGIC_ENABLE = no       # Virtual DIP switch configuration(+1000)
-MOUSEKEY_ENABLE = yes       # Mouse keys(+4700)
-EXTRAKEY_ENABLE = yes       # Audio control and System control(+450)
-CONSOLE_ENABLE = no         # Console for debug(+400)
-COMMAND_ENABLE = yes        # Commands for debug and configuration
-NKRO_ENABLE = no           # Nkey Rollover - if this doesn't work, see here: https://github.com/tmk/tmk_keyboard/wiki/FAQ#nkro-doesnt-work
-BACKLIGHT_ENABLE = no       # Enable keyboard backlight functionality
-MIDI_ENABLE = no            # MIDI controls
-AUDIO_ENABLE = no           # Audio output on port C6
-UNICODE_ENABLE = no         # Unicode
-BLUETOOTH_ENABLE = no       # Enable Bluetooth with the Adafruit EZ-Key HID
-RGBLIGHT_ENABLE = yes        # Enable WS2812 RGB underlight. 
-SLEEP_LED_ENABLE = no       # Breathing sleep LED during USB suspend
-