Add links to `impl period` blog post and gitter.im
# `bindgen`
+[`impl period`](https://blog.rust-lang.org/2017/09/18/impl-future-for-rust.html) has been started! Join us at [Gitter.im](https://gitter.im/rust-impl-period/WG-dev-tools-bindgen).
+
**`bindgen` automatically generates Rust FFI bindings to C and C++ libraries.**
For example, given the C header `doggo.h`:
