Naming and coding style convention, new linter tool. (#945)

* Makefile, Scripts: new linter
* About: remove ID from IC
* Firmware: remove double define for DIVC/DIVR
* Scripts: check folder names too. Docker: replace syntax check with make lint.
* Reformat Sources and Migrate to new file naming convention
* Docker: symlink clang-format-12 to clang-format
* Add coding style guide

applications/lfrfid_debug/scene/lfrfid_debug_app_scene_start.h

@@ -0,0 +1,13 @@
+#pragma once
+#include "../lfrfid_debug_app.h"
+
+class LfRfidDebugAppSceneStart : public GenericScene<LfRfidDebugApp> {
+public:
+    void on_enter(LfRfidDebugApp* app, bool need_restore) final;
+    bool on_event(LfRfidDebugApp* app, LfRfidDebugApp::Event* event) final;
+    void on_exit(LfRfidDebugApp* app) final;
+
+private:
+    void submenu_callback(void* context, uint32_t index);
+    uint32_t submenu_item_selected = 0;
+};