[keyboard] Project Keyboard Signature 87 (#9062)

* preliminary check in, basically a copy from 159's github with a few additions to get it to compile

* update readme

* fixup the LAYOUT macro labels to be more reasonable

* add tkl_ansi LAYOUT macro for community layout support

* clean up rules.mk, add community layout suport, and add in bootloader

* add a tsangan layout macro

* spruce up readme

* add VIA keymap

* add qmk configurator support

* Update keyboards/projectkb/signature87/rules.mk

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/projectkb/signature87/rules.mk

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/projectkb/signature87/rules.mk

Co-authored-by: Joel Challis <git@zvecr.com>

* remove unneeded file

* Update keyboards/projectkb/signature87/config.h

Co-authored-by: Joel Challis <git@zvecr.com>

* Update keyboards/projectkb/signature87/rules.mk

Co-authored-by: Ryan <fauxpark@gmail.com>

* Update keyboards/projectkb/signature87/config.h

Co-authored-by: Joel Challis <git@zvecr.com>
Co-authored-by: Ryan <fauxpark@gmail.com>

keyboards/projectkb/signature87/rules.mk

@@ -0,0 +1,19 @@
+# MCU name
+MCU = STM32F072
+
+# Build Options
+#   comment out to disable the options.
+#
+#BOOTMAGIC_ENABLE = yes	# Virtual DIP switch configuration
+MOUSEKEY_ENABLE = yes	# Mouse keys
+EXTRAKEY_ENABLE = yes	# Audio control and System control
+CONSOLE_ENABLE = yes	# Console for debug
+COMMAND_ENABLE = yes    # Commands for debug and configuration
+SLEEP_LED_ENABLE = yes  # Breathing sleep LED during USB suspend
+NKRO_ENABLE = yes	    # USB Nkey Rollover
+BACKLIGHT_ENABLE = no
+
+# Enter lower-power sleep mode when on the ChibiOS idle thread
+OPT_DEFS += -DCORTEX_ENABLE_WFI_IDLE=TRUE
+
+LAYOUTS = tkl_ansi