create /apps/temapltes/ structure, clean up cmake files to use directory name for binary name directly

apps/templates/c/CMakeLists.txt

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.21)
+project(twngame LANGUAGES C)
+
+if(NOT CMAKE_BUILD_TYPE)
+        set(CMAKE_BUILD_TYPE Debug)
+endif()
+
+add_subdirectory($ENV{TWNROOT} $ENV{TWNROOT}/build)
+
+set(SOURCE_FILES
+        game.c
+        state.h
+)
+
+cmake_path(GET CMAKE_SOURCE_DIR STEM LAST_ONLY GAME_PROJECT_NAME)
+use_townengine(${GAME_PROJECT_NAME} "${SOURCE_FILES}" ${CMAKE_CURRENT_SOURCE_DIR})