move platformes and scenery to /apps/demos/

apps/demos/scenery/CMakeLists.txt

@@ -0,0 +1,20 @@
+cmake_minimum_required(VERSION 3.21)
+
+project(scenery LANGUAGES C)
+
+if(NOT CMAKE_BUILD_TYPE)
+        set(CMAKE_BUILD_TYPE Debug)
+endif()
+
+add_subdirectory($ENV{TWNROOT} $ENV{TWNBUILDDIR})
+
+set(SOURCE_FILES
+        game.c
+        state.h
+
+        scenes/scene.c scenes/scene.h
+        scenes/title.c scenes/title.h
+        scenes/ingame.c scenes/ingame.h
+)
+
+use_townengine(${PROJECT_NAME} "${SOURCE_FILES}" ${CMAKE_CURRENT_SOURCE_DIR})