feat(source/path): ignore root slash

[alexandre-abrioux]

Context

When writing .gitignore files (or .dockerignore files, etc...), we can prepend the directories to ignore with a forward slash to only ignore the first level directory on a project, e.g.:

# Content of .gitignore
/dist/

This will ignore project_root/dist/, and won't ignore project_root/foo/dist/.

Issue

When writing such ignore rules, it is convenient to only autocomplete a list of directories in the current project. This is not possible currently with the path source, as using a forward slash autocompletes a list contained at the filesystem root path.

Proposal

I propose introducing a new option: ignore_root_slash, which would always look for directories in the current project, rather than listing directories in the file root path.

[Saghen]

Thank you!