fixed small typo in readme
This repository is the central place for Rust development of the [libp2p](https://libp2p.io) spec.
-**Warning**: While we are trying our best to be compatible with other lib2p implementations, we
+**Warning**: While we are trying our best to be compatible with other libp2p implementations, we
cannot guarantee that this is the case considering the lack of a precise libp2p specifications.
## Documentation
