Break out the game demo into multiple source and include files, add a bunch of missing assets, conform to the new subsystems interface from libakgl

CMakeLists.txt

@@ -20,8 +20,19 @@ set(libdir      "\${exec_prefix}/lib")
 set(includedir  "\${prefix}/include")
 
 # Add include directories
-include_directories(${SDL3_INCLUDE_DIRS})
-add_executable(akgltest src/akgltest.c)
+include_directories(${SDL3_INCLUDE_DIRS} include/)
+add_executable(akgltest
+  src/actors.c
+  src/audio.c
+  src/events.c
+  src/controllers.c
+  src/gamemodes.c
+  src/init.c
+  src/SDL_AppInit.c
+  src/SDL_AppQuit.c
+  src/SDL_AppIterate.c
+  src/main.c
+)
 
 target_link_libraries(akgltest
   PRIVATE