Macros in JSON keymaps (#14374)

* macros in json keymaps

* add advanced macro support to json

* add a note about escaping macro strings

* add simple examples

* format json

* add support for language specific keymap extras

* switch to dictionaries instead of inline text for macros

* use SS_TAP on the innermost tap keycode

* add the new macro format to the schema

* document the macro limit

* add the json keyword for syntax highlighting

* fix format that vscode screwed up

* Update feature_macros.md

* add tests for macros

* change ding to beep

* add json support for SENDSTRING_BELL

* update doc based on feedback from sigprof

* document host_layout

* remove unused var

* improve carriage return handling

* support tab characters as well

* Update docs/feature_macros.md

Co-authored-by: Nick Brassel <nick@tzarc.org>

* escape backslash characters

* format

* flake8

* Update quantum/quantum_keycodes.h

Co-authored-by: Nick Brassel <nick@tzarc.org>

requirements-dev.txt

@@ -5,4 +5,5 @@
 nose2
 flake8
 pep8-naming
+pyflakes
 yapf