Refactor new-keyboard to be python3.7 compatible (#14707)

* Use copy_tree from distutils for python 3.7 support

* Bump python version in docs

* Changed new-keyboard to use printf-style format strings

* Use username for manunfacturer / maintainer

* Update lib/python/qmk/cli/new/keyboard.py

Co-authored-by: Zach White <skullydazed@drpepper.org>

Co-authored-by: Zach White <skullydazed@drpepper.org>

data/templates/base/%(KEYBOARD)s.c

@@ -0,0 +1,4 @@
+// Copyright %(YEAR)s %(YOUR_NAME)s (@%(USER_NAME)s)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "%(KEYBOARD)s.h"