Keymap: Add unagi planck keymap (#3527)

* modifications to add mouse buttons 1-4 and misc

* Add khord chocopad keymap

* fix merge message

* Add unagi keymap

* Add readme for unagi planck keymap

* Replace boilerplate for unagi keymap

keyboards/planck/keymaps/unagi/config.h

@@ -0,0 +1,41 @@
+#pragma
+
+#ifdef AUDIO_ENABLE
+    #define STARTUP_SONG SONG(SONIC_RING)
+    // #define STARTUP_SONG SONG(NO_SOUND)
+    #define MUSIC_ON_SONG SONG(ZELDA_PUZZLE)
+
+    #define DEFAULT_LAYER_SONGS { SONG(QWERTY_SOUND), \
+                                  SONG(COLEMAK_SOUND), \
+                                  SONG(DVORAK_SOUND) \
+                                }
+#endif
+
+#define TAPPING_TERM 200
+
+/*
+ * 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
+
+// Most tactile encoders have detents every 4 stages
+#define ENCODER_RESOLUTION 4