Beef up how qmk doctor works. (#7375)

* Beef up how `qmk doctor` works.

* improve the `git submodule status` parsing. h/t @erovia

* Fix whitespace and imports

* yapf

* Add documentation for the new doctor functionality

* Replace type_unchanged() with str()

* remove unused modules

* Update lib/python/qmk/cli/doctor.py

Co-Authored-By: Erovia <Erovia@users.noreply.github.com>

Co-authored-by: Erovia <Erovia@users.noreply.github.com>

docs/cli.md

@@ -141,14 +141,28 @@ qmk docs [-p PORT]
 
 ## `qmk doctor`
 
-This command examines your environment and alerts you to potential build or flash problems.
+This command examines your environment and alerts you to potential build or flash problems. It can fix many of them if you want it to.
 
 **Usage**:
 
 ```
-qmk doctor
+qmk doctor [-y] [-n]
 ```
 
+**Examples**:
+
+Check your environment for problems and prompt to fix them:
+
+    qmk doctor
+
+Check your environment and automatically fix any problems found:
+
+    qmk doctor -y
+
+Check your environment and report problems only:
+
+    qmk doctor -n
+
 ## `qmk json-keymap`
 
 Creates a keymap.c from a QMK Configurator export.