Added all original S60-X keymaps

All keymaps that were included in VinnyCordeiro's repository were ported to QMK.
Main Readme was copied over from VC's repo, slightly altered.
Main Makefile was updated to reflect VC's original configuration.
Small changes in felix keymap.

keyboards/s60-x/keymaps/plain/keymap.c

@@ -0,0 +1,25 @@
+#include "keymap_common.h"
+
+/* Main layer:
+┌─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┐
+│ ESC │  1  │  2  │  3  │  4  │  5  │  6  │  7  │  8  │  9  │  0  │  -  │  =  │▒▒▒▒▒│BKSPC│
+├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
+│ TAB │  Q  │  W  │  E  │  R  │  T  │  Y  │  U  │  I  │  O  │  P  │  [  │  ]  │  \  │█████│
+├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
+│CAPSL│  A  │  S  │  D  │  F  │  G  │  H  │  J  │  K  │  L  │  ;  │  '  │▒▒▒▒▒│ENTER│█████│
+├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
+│LSHFT│▒▒▒▒▒│  Z  │  X  │  C  │  V  │  B  │  N  │  M  │  ,  │  .  │  /  │▒▒▒▒▒│RSHFT│▒▒▒▒▒│
+├─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
+│LCTRL│L_GUI│L_ALT│█████│█████│█████│ SPC │█████│█████│█████│R_ALT│R_GUI│ APP │RCTRL│█████│
+└─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
+*/
+
+const uint8_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
+    /* 0: qwerty */
+    KEYMAP(ESC,    1,    2,   3,   4,   5,   6,   7,   8,    9,    0, MINS, EQL,    NO, BSPC, \
+           TAB,    Q,    W,   E,   R,   T,   Y,   U,   I,    O,    P, LBRC, RBRC, BSLS,       \
+          CAPS,    A,    S,   D,   F,   G,   H,   J,   K,    L, SCLN, QUOT, NO,   ENT,        \
+          LSFT,   NO,    Z,   X,   C,   V,   B,   N,   M, COMM,  DOT, SLSH, NO,   RSFT,   NO, \
+          LCTL, LGUI, LALT,                SPC,                 RALT, RGUI, APP,  RCTL),
+};
+const uint16_t PROGMEM fn_actions[] = {};