[Keymap] Add spidey3 keymap for 75_ansi, and a spidey3 userspace (#8470)

* First cut at Josh Diamond's KBD75 customizations.
Includes:
* My unique keymap with ChromeOS specific keys
* Use RGB underglow to indicate Caps Lock
* Some unicode bindings
* Some changes to make debugging easier

* Updated spidey3 to be applicable to all 75_ansi boards

* Sadly, ChromeOS doesn't pay attention to most consumer codes

* Add mac layer; fix flakeyness in CAPS_LOCK underglow.

* Make layers.json match the keymap (to the extent possible)

* Major cleanup; fix broken debug persistence

* Cleanup some whitespace issues

* Fix incorrect log message.

* Rework layer indication to user RGBLIGHT_LAYERS

* Update layouts/community/75_ansi/spidey3/keymap.c

Co-Authored-By: Drashna Jaelre <drashna@live.com>

* Rename users/spidey3/rgblight.c to layer_rgb.c per suggestion

* Refactor to use set_single_persistant_default_layer().

* Use dprint/f to make logging more elegant.

* Update users/spidey3/config.h

Co-Authored-By: Drashna Jaelre <drashna@live.com>

* Update users/spidey3/config.h

Co-Authored-By: Drashna Jaelre <drashna@live.com>

* Update layouts/community/75_ansi/spidey3/rules.mk

Co-Authored-By: Ryan <fauxpark@gmail.com>

* Update users/spidey3/spidey3.c

Co-Authored-By: Ryan <fauxpark@gmail.com>

* Update users/spidey3/layer_rgb.c

Co-Authored-By: Ryan <fauxpark@gmail.com>

* Update users/spidey3/init.c

Co-Authored-By: Ryan <fauxpark@gmail.com>

* Changes from code review

Co-authored-by: Joshua Diamond <jdiamond@Deep-Thought.local>
Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>

users/spidey3/unicode.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include QMK_KEYBOARD_H
+
+#ifdef UNICODEMAP_ENABLE
+
+enum unicode_names {
+    BUL1,
+    BUL2,
+    LARR,
+    RARR,
+    ENDASH,
+    EMDASH,
+};
+
+#define X_BUL (XP(BUL1, BUL2))
+#define X_DASH (XP(ENDASH, EMDASH))
+
+#endif