## Summary
First piece of https://github.com/astral-sh/uv/issues/313. In order to
support unnamed requirements, we need to be able to parse them in
`requirements-txt`, which in turn means that we need to introduce a new
type that's distinct from `pep508::Requirement`, given that these
_aren't_ PEP 508-compatible requirements.
Part of: https://github.com/astral-sh/uv/issues/313.
Charlie Marsh