Add missing conv.rs file
This repo holds an API for 2D graphics drawing.
The motivation for this crate is set forth in this blog post. Ideally it will become a layer to help druid become cross-platform.
This repo is structured as a core API crate, "piet" and a separate crate for each back-end, currently "piet-direct2d" and "piet-cairo". One motivation for this structure is that additional back-ends can be written without coupling to the main crate, and clients can opt in to the back-ends they need. In addition, it's possible use multiple back-ends, which will likely be useful for testing.
A companion for Bézier path representation and geometry is kurbo.
Contributions are welcome! It's in early stages, so there are lots of opportunities to fill things out.