Enhance build system and project documentation

Added LICENSE file with MIT License and copyright notice.
Added preview.png binary file for project assets.
Changed CMakeLists.txt to include asset copying command.
Changed mesh loading in Mesh.c to support smooth normals.
Changed ray origin biasing in PathTracing.c and shadow rays.
Changed ray-triangle intersection logic in RayIntersection.c.
Changed ray_intersect_bvh_count function in Debug.c to static.
Changed rendering functions in Scene.c with TODO for optimization.
Updated README.md with project description and build instructions.
Updated window dimensions in main.c for testing purposes.

CMakeLists.txt

@@ -54,15 +54,21 @@ set_target_properties(${PROJECT_NAME} PROPERTIES
 )
 
 if(WIN32)
-  add_custom_command(
-    TARGET ${PROJECT_NAME} POST_BUILD
-    COMMAND ${CMAKE_COMMAND} -E copy
+    add_custom_command(
+        TARGET ${PROJECT_NAME} POST_BUILD
+        COMMAND ${CMAKE_COMMAND} -E copy
             $<TARGET_RUNTIME_DLLS:${PROJECT_NAME}>
             $<TARGET_FILE_DIR:${PROJECT_NAME}>
-    VERBATIM
-    COMMAND_EXPAND_LISTS
+        VERBATIM
+        COMMAND_EXPAND_LISTS
   )
 endif()
 
-# file(COPY ${LIBRARY_PATH}/cglm.dll DESTINATION ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/)
-# file(COPY ${LIBRARY_PATH}/assimp-vc143-mt.dll DESTINATION ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/)
+add_custom_command(
+    TARGET ${PROJECT_NAME} PRE_BUILD
+    COMMAND ${CMAKE_COMMAND} -E copy_directory
+        ${CMAKE_SOURCE_DIR}/assets
+        $<TARGET_FILE_DIR:${PROJECT_NAME}>/assets
+)
+
+file(COPY ${CMAKE_SOURCE_DIR}/assets DESTINATION ${CMAKE_BINARY_DIR})