--output-directory misbehaves if a trailing slash is not included.

[marcusround]

Running the following command in Windows 11 terminal
./ysc.exe tag --output-directory output game.yarn

Expected behaviour is to output a file game.yarn in a subfolder named output of the current directory.
Instead what happens is a file called outputgame.yarn is created in the current directory.

Interestingly, the output will still fail with "Directory does not exist", if subfolder output does not exist. But it just doesn't get used.

To achieve the expected behaviour, I must run the following command
./ysc.exe tag --output-directory output/ game.yarn