Keymap: xtonhasvim Levinson (#3837)

* pulled in levinson from staging.

* simplified trilayer handling

and some other linting that bit me in the last code review

* formatting

keyboards/levinson/keymaps/xtonhasvim/config.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#define USE_SERIAL
+
+// #define MUSIC_MASK (keycode != KC_NO)
+
+/*
+ * MIDI options
+ */
+
+/* Prevent use of disabled MIDI features in the keymap */
+//#define MIDI_ENABLE_STRICT 1
+
+/* enable basic MIDI features:
+   - MIDI notes can be sent when in Music mode is on
+*/
+
+// #define MIDI_BASIC
+
+/* enable advanced MIDI features:
+   - MIDI notes can be added to the keymap
+   - Octave shift and transpose
+   - Virtual sustain, portamento, and modulation wheel
+   - etc.
+*/
+//#define MIDI_ADVANCED
+
+/* override number of MIDI tone keycodes (each octave adds 12 keycodes and allocates 12 bytes) */
+//#define MIDI_TONE_KEYCODE_OCTAVES 2
+
+// help for fast typist+dual function keys?
+#define PERMISSIVE_HOLD
+
+// where is the cord plugged in?
+#define MASTER_LEFT