InfiniTime/doc/watchfaces.md

# Adapting old watchfaces:
 - When resolving conflicts, delete clock.h/.cpp, keep both in CMakeLists.cpp, accept current in SettingWatchFace.cpp, and keep both if there are any changes in fonts.
 - Add entry to WatchFace enum in displayapp/apps/Apps.h.in
 - Remove `DisplayApp* app` param from constructor in .h and .cpp and remove Screen(app) from initializer list on constructor in .cpp
 - Add const to batteryController and bleController is present in constructor params and in private members in .h
 - In .cpp, remove `#include <date/date.h>` and convert calls to get time to format like in working watch faces. For example:
```cpp
    auto newDateTime = currentDateTime.Get();

    auto dp = date::floor<date::days>(newDateTime);
    auto time = date::make_time(newDateTime - dp);

    uint8_t hour = time.hours().count();
    uint8_t minute = time.minutes().count();
```
with
```cpp
    uint8_t hour = dateTimeController.Hours();
    uint8_t minute = dateTimeController.Minutes();
```
, add 
```cpp
Utility::DirtyValue<std::chrono::time_point<std::chrono::system_clock, std::chrono::days>> currentDate;
```
to .h
 - Remove `motionSensorOk = motionController.IsSensorOk();` and reference to `motionSensorOk` in following if
 - In .h add `#include "utility/DirtyValue.h"` and replace all `DirtyValue<>` vars with `Utility::DirtyValue<>`
 - Add WatchFaceTraits:
 ``` cpp
     template <>
    struct WatchFaceTraits<WatchFace::Digital> {
      static constexpr WatchFace watchFace = WatchFace::Digital;
      static constexpr const char* name = "Digital face";

      static Screens::Screen* Create(AppControllers& controllers) {
        return new Screens::WatchFaceDigital(controllers.dateTimeController,
                                             controllers.batteryController,
                                             controllers.bleController,
                                             controllers.notificationManager,
                                             controllers.settingsController,
                                             controllers.heartRateController,
                                             controllers.motionController,                                             controllers.filesystem
                                             *controllers.weatherController);
      };
  

      static bool IsAvailable(Pinetime::Controllers::FS& filesystem) {
        return Screens::WatchFaceCasioStyleG7710::IsAvailable(filesystem);
      }
    };
```
modify as necesary.
- Add include to UserApps.h: `#include "displayapp/screens/WatchFace---.h"`
- Add to displayapp/apps/CMakeLists.txt