[Keyboard] Add "Uno" rev2 (#14071)

* [Keyboard] Add "Uno" rev2

Adds support for the second revision of Uno, courtesy of @Snipeye.

* Update keyboards/uno/rev2/rules.mk

* Update keyboards/uno/rev1/rules.mk

* Update keyboards/uno/uno.h

* Update keyboards/uno/rev2/rules.mk

* Update keyboards/uno/rev1/rules.mk

* Update keyboards/uno/keymaps/demo/keymap.c

* Update keyboards/uno/keymaps/demo/keymap.c

* Update keyboards/uno/keymaps/demo/keymap.c

* Update keyboards/uno/rev2/rules.mk

* Update keyboards/uno/rev1/rules.mk

* Align rules.mk comments

* Update keyboards/uno/info.json

* Update keyboards/uno/rev1/config.h

* Update keyboards/uno/rev2/config.h

* Update keyboards/uno/rev2/config.h

* Update keyboards/uno/rev2/config.h

* Update keyboards/uno/rev1/config.h

keyboards/uno/rev2/rev2.h

@@ -0,0 +1,25 @@
+/* Copyright 2020 Snipeye
+ *
+ * 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 "quantum.h"
+
+#define LAYOUT( \
+  K00  \
+) { \
+  { K00 } \
+}