Add v.toml

[ethanolchik]

Hello! This pull request will add v.toml. its my first time doing this so please correct me if i did something wrong.

[dan-stowell]

Good afternoon @classerase ! You've probably noticed by now that we've been slow to merge community PRs on polygott. We've decided to focus on giving Repl.it a stable foundation instead of adding features and updating languages. Once we and our community feel comfortable with Repl.it's overall stability, we'll give this change another look. Thank you for contributing!