`set working-directory` should create that dir if missing about just HOT 3 CLOSED

@laniakea64 brilliant idea, thanks! Totally solves my problem.

Now the only problem left is the un-readable error message. I think just should check if working directory already exists before running the recipe (unless it has [no-cd]) -- this way users will get much better error than this one:

error: Recipe ... could not be run because just could not find the shell: No such file or directory (os error 2)

from just.

Another problem with creating the working directory is that it would mask typos, i.e., the working directory does exist, but you misspelled it in the justfile, just would create it and continue instead of erroring. I do think improving the error message is a good idea though, feel free to create a separate issue!

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The proposed ideas won't help with the stated problem and trying to use them that way would be a mess. Also, they would break backwards compatibility.

A smoother solution that quick test indicates would already work in current just would be something like

set working-directory := 'repodir'

[no-cd]
init:
    cd {{quote(justfile_directory())}} && if test ! -d repodir;then git clone ...;fi

from just.