[Keyboard] Add Lagom keyboard (#19240)

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

keyboards/sthlmkb/lagom/config.h

@@ -0,0 +1,30 @@
+/*
+Copyright 2022 mohoyt
+
+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
+
+#include "config_common.h"
+
+/* key matrix size */
+#define MATRIX_ROWS 5
+#define MATRIX_COLS 16
+#define MATRIX_MUX_COLS 4
+
+#define MATRIX_ROW_PINS { B6, B2, B3, B1, F7 }
+#define MATRIX_COL_PINS { }
+#define MATRIX_COL_MUX_PINS { D7, E6, B4, B5 }
+