[Keyboard] Add handwired Split 5x7 (#18128)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>

keyboards/handwired/stef9998/split_5x7/keymaps/default/config.h

@@ -0,0 +1,28 @@
+/*
+Copyright 2022 stef9998
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#pragma once
+
+/* Use I2C or Serial, not both */
+// #define USE_SERIAL
+#define USE_I2C
+
+/* Select hand configuration */
+// #define MASTER_LEFT
+// #define MASTER_RIGHT
+#define EE_HANDS
+