Support both AVR and ps2avrGB targets for new_project script (#2811)

* Stopping point at creating targets for new_project script

* Add second argument for target

* Add the ps2avrgb target

* consider the case where the firmware type target is not valid

* fix template files to be more generic

* Code cleanup

* Change variable name to be more descriptive

* make avr the default

* forgot to put the template files in

* Take out useless comments

* add usage info

quantum/template/avr/template.h

@@ -0,0 +1,34 @@
+/* Copyright 2017 REPLACE_WITH_YOUR_NAME
+ *
+ * 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/>.
+ */
+#ifndef %KEYBOARD_UPPERCASE%_H
+#define %KEYBOARD_UPPERCASE%_H
+
+#include "quantum.h"
+
+// This a shortcut to help you visually see your layout.
+// The following is an example using the Planck MIT layout
+// The first section contains all of the arguments
+// The second converts the arguments into a two-dimensional array
+#define LAYOUT( \
+    k00, k01, k02, \
+      k10,  k11   \
+) \
+{ \
+    { k00, k01,   k02 }, \
+    { k10, KC_NO, k11 }, \
+}
+
+#endif