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/info.json

@@ -1,7 +1,7 @@
 {
-    "keyboard_name": "%KEYBOARD%",
+    "keyboard_name": "%(KEYBOARD)s",
     "url": "",
-    "maintainer": "%YOUR_NAME%",
+    "maintainer": "%(USER_NAME)s",
     "layouts": {
         "LAYOUT": {
             "layout": [