Search both current directory and repo root

[antoine-gallix]

This cover the use case where the current directory is inside a repo, the virtual environment being in the current directory, but not at the root of the repository. This is a common case in companies following monorepo pattern, where all modules of a system are in the same repo, and where dev would work in one of those module directories, and create virtual environment there.

[nakulj]

In what order will this search the target directories? I think we'd want to search the working directory first, then the repository directory.

[antoine-gallix]

Experimenting with multiple list expansion in fish:

set A a1 a2;set B b1 b2
for cat in $A/$B
    echo $cat
end

a1/b1
a2/b1
a1/b2
a2/b2

Not what I expected, but it confirms that the final loop is more like:

for envdir in env .env venv .venv
    for dir in current repo_root
        try repo_root/envdir

[everyx]

@nakulj Can we merge this PR now?