[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/config.h

@@ -15,8 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef CONFIG_H
-#define CONFIG_H
+#pragma once
 
 #include "config_common.h"
 
@@ -26,7 +25,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define DEVICE_VER      0x0001
 #define MANUFACTURER    Maple Computing
 #define PRODUCT         The PCB Ruler
-#define DESCRIPTION     A custom keyboard PCB ruler, can also function as a macro pad
+#define DESCRIPTION     "A custom keyboard PCB ruler, can also function as a macro pad"
 
 /* key matrix size */
 #define MATRIX_ROWS 1
@@ -155,5 +154,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define RGBLIGHT_HUE_STEP 10
 #define RGBLIGHT_SAT_STEP 17
 #define RGBLIGHT_VAL_STEP 17
-
-#endif