Keyboard: Add support for Diverge TM2 (#3829)

* pulling in diverge tm2 from staging branch

* cleaned up comments, docs, licenses

* refactored apparent grid to make 2u spacebars more obvious

* various delinting from noroadsleft review

* most of drashna's feedback responded to

- lots of lint swept
- used more modern tri-layer functions
- still need to adopt modern split support.

* switch to common split code. remove comment cruft

* tapping force hold makes LT way more usable for rapid ,  sequences

keyboards/divergetm2/keymaps/default/config.h

@@ -0,0 +1,23 @@
+/* Copyright 2018 Christon DeWan (xton)
+ * Copyright 2017 IslandMan93
+ *
+ * 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
+
+// place overrides here
+#define MASTER_RIGHT
+#define PERMISSIVE_HOLD
+#define TAPPING_TERM 150