Borrowed joint Shift/Enter idea from sgoodwin mapping

keyboards/planck/keymaps/cbbrowne/keymap.c

@@ -84,7 +84,7 @@ enum macro_id {
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 [_QW] = { /* Qwerty */
   {KC_ESC,  KC_Q,    KC_W,    KC_E,    KC_R,    KC_T,    KC_Y,    KC_U,    KC_I,    KC_O,    KC_P,    KC_BSPC},
-  {KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, KC_ENT},
+  {KC_LCTL, KC_A,    KC_S,    KC_D,    KC_F,    KC_G,    KC_H,    KC_J,    KC_K,    KC_L,    KC_SCLN, MT(MOD_RSFT, KC_ENT)},
   {KC_LSFT, KC_Z,    KC_X,    KC_C,    KC_V,    KC_B,    KC_N,    KC_M,    KC_COMM, KC_DOT,  KC_SLSH, KC_QUOT },
   {KC_TAB,  M(M_LED), KC_LALT, KC_LGUI, MO(_LW), KC_SPC,  KC_SPC,  MO(_RS), KC_LEFT, KC_DOWN, KC_UP,   KC_RGHT}
   /* Note that KC_SPC is recorded TWICE, so that either matrix position can activate it */

keyboards/planck/keymaps/cbbrowne/readme.md

@@ -77,3 +77,4 @@ doing sundry experimentation:
   * The jeebak keymap seems to have some neat ideas:
     - Number layer which is aggressive about having numbers in several places
     - Touch layer seems interesting
+  * Trying out sgoodwin's "hold Enter down to get Shift"