Added Split Backspace Support for the Nemui (#11131)

* added nemui layout

* via support working

* added license headers for c and h files

* Update keyboards/nemui/keymaps/via/rules.mk

Co-authored-by: Drashna Jaelre <drashna@live.com>

* Update keyboards/nemui/nemui.c

Co-authored-by: Drashna Jaelre <drashna@live.com>

* Update keyboards/nemui/config.h

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

* Update keyboards/nemui/readme.md

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

* Update keyboards/nemui/rules.mk

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

* removed nemui.json as it was supposed to only be in via repo

* Update keyboards/nemui/keymaps/default/keymap.c

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

* Update keyboards/nemui/info.json

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

* Update keyboards/nemui/info.json

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

* Update keyboards/nemui/keymaps/via/keymap.c

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

* Update keyboards/nemui/keymaps/via/keymap.c

Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

* added split backspace support for the nemui

* need to also update the qmk keymap

* fixed info.json to have the new keys

* vusb changes shouldn't have happened

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: James Young <18669334+noroadsleft@users.noreply.github.com>

keyboards/nemui/info.json

@@ -62,7 +62,12 @@
     {
       "x": 13,
       "y": 0,
-      "w": 2
+      "w": 1
+    },
+    {
+      "x": 14,
+      "y": 0,
+      "w": 1
     },
     {
       "x": 0,