v0.1.0

First tagged version.

Added

• scripts/rust_crate_to_workspace.sh: moves src and Cargo.toml into <folder>/<crate>/ (default folder rust)
  and stages a workspace Cargo.toml with <folder>/* as members.
• Smoke test (tests/smoke.sh) and CI on Linux and macOS.

Fixed

• The dirty git tree check never fired; it now refuses on any uncommitted change.
• Refuses when the target folder already exists, outside a git repository root, or without a [package] name.
• Works with bash 3.2 and BSD tools (no GNU-only mkdir --parents, \s in grep and sed, realpath).
• Errors go to stderr.