QMK CLI and JSON keymap support (#6176)

* Script to generate keymap.c from JSON file.

* Support for keymap.json

* Add a warning about the keymap.c getting overwritten.

* Fix keymap generating

* Install the python deps

* Flesh out more of the python environment

* Remove defunct json2keymap

* Style everything with yapf

* Polish up python support

* Hide json keymap.c into the .build dir

* Polish up qmk-compile-json

* Make milc work with positional arguments

* Fix a couple small things

* Fix some errors and make the CLI more understandable

* Make the qmk wrapper more robust

* Add basic QMK Doctor

* Clean up docstrings and flesh them out as needed

* remove unused compile_firmware() function

docs/cli.md

@@ -0,0 +1,31 @@
+# QMK CLI
+
+This page describes how to setup and use the QMK CLI.
+
+# Overview
+
+The QMK CLI makes building and working with QMK keyboards easier. We have provided a number of commands to help you work with QMK:
+
+* `qmk compile-json`
+
+# Setup
+
+Simply add the `qmk_firmware/bin` directory to your `PATH`. You can run the `qmk` commands from any directory.
+
+```
+export PATH=$PATH:$HOME/qmk_firmware/bin
+```
+
+You may want to add this to your `.profile`, `.bash_profile`, `.zsh_profile`, or other shell startup scripts.
+
+# Commands
+
+## `qmk compile-json`
+
+This command allows you to compile JSON files you have downloaded from <https://config.qmk.fm>.
+
+**Usage**:
+
+```
+qmk compile-json mine.json
+```