review: Contributing -> Development.

Signed-off-by: Piotr Sikora <[email protected]>

Author: PiotrSikora

README.md

@@ -28,7 +28,7 @@
 - [Extending Envoy with WASM and Rust](https://antweiss.com/blog/extending-envoy-with-wasm-and-rust/)
 - [Writing Envoy filters in Rust with WebAssembly](https://content.red-badger.com/resources/extending-istio-with-rust-and-webassembly)
 
-## Contributing
+## Development
 
 ### Testing