Improve the 'Features' section (README.md)
- [Contributing](https://github.com/teloxide/teloxide#contributing)
## Features
+ - **Declarative API.** You tell teloxide what you want instead of describing what to do.
+
- **Type-safe.** teloxide leverages the Rust's type system with two serious implications: resistance to human mistakes and tight integration with IDEs. Write fast, avoid debugging as much as possible.
- - **Flexible API.** teloxide gives you the power of [streams](https://docs.rs/futures/0.3.4/futures/stream/index.html): you can combine [all 30+ patterns](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html) when working with updates from Telegram.
+ - **Flexible API.** teloxide gives you the power of [streams](https://docs.rs/futures/0.3.4/futures/stream/index.html): you can combine [all 30+ patterns](https://docs.rs/futures/0.3.4/futures/stream/trait.StreamExt.html) when working with updates from Telegram. Feel free to glue handlers both horizontally and vertically.
- **Persistency.** By default, teloxide stores all user dialogues in RAM, but you can store them somewhere else (for example, in DB) just by implementing 2 functions.
