Sets3n kk980 Layout Macro Refactor (#15039)

* physically arrange layout macro

Arranges the layout macro to resemble the keyboard layout, and updates the keymaps to match.

* use 3-character notation for position identifiers in kk980.h

* add matrix diagram to kk980.h

* fix syntax error in info.json

Apparently the API doesn't care about this error... but QMK Configurator does if you use the local import mode (Ctrl+Shift+I).

keyboards/sets3n/kk980/info.json

@@ -106,11 +106,10 @@
                 {"label":"DOWN", "x": 14.25, "y": 5.75},
                 {"label":"RIGHT", "x": 15.25, "y": 5.75},
                 {"label":"0", "x": 16.5, "y": 5.5},
-                {"label":".DEL", "x": 17.5, "y": 5.5,},
+                {"label":".DEL", "x": 17.5, "y": 5.5},
                 {"label":"ENTER", "x": 18.5, "y": 4.5, "h": 2}
 
             ]
         }
     }
 }
-