Test mains for libft project at Hive Helsinki 42 School

Usage once in libft-testset/:
make [ft_function] [--ignore-errors]
./run_tests.sh | grep KO
./_programs/ft_function/ft_function

.vscode/ directory has debugging instructions.
Visual Studio Code:
File -> Open... directory containing libft/ to be tested and libft-testset/.
Move .vscode/launch.json and .vscode/tasks.json into workspaceFolder level directory ./vscode in VSCode.