Add a newbie guide for people completely new to QMK (#2480)

docs/redirects.json

@@ -16,6 +16,10 @@
                 "from": "feature_common_shortcuts.html",
                 "to": "feature_advanced_keycodes.html"
             },
+            {
+                "from": "flashing.html",
+                "to": "newbs_flashing.html"
+            },
             {
                 "from": "key_lock.html",
                 "to": "feature_key_lock.html"