make build directory now prefixed with dot, as it what clangd expects, remove .clangd file

CMakeLists.txt

@@ -340,8 +340,3 @@ include_deps(${TWN_TARGET})
 link_deps(${TWN_TARGET})
 target_link_libraries(${TWN_TARGET} PUBLIC twn_third_parties)
 target_include_directories(${TWN_TARGET} PRIVATE ${TWN_ROOT_DIR}/src)
-
-# move compie_commands.json into root directory so that it plays nicer with code editors without any configuration
-add_custom_target(copy-compile-commands ALL
-                 ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_BINARY_DIR}/compile_commands.json
-                                                       ${TWN_ROOT_DIR})