remove tide::prelude from simple examples

Author: jbr

README.md

@@ -23,7 +23,6 @@ $ cargo add -D tide-testing
 ## Example usage:
 
 ```rust
-use tide::prelude::*;
 let mut app = tide::new();
 app.at("/").get(|_| async { Ok("hello!") });
 

src/lib.rs

@@ -17,7 +17,6 @@
 //!
 //! ```rust
 //! # fn main() -> tide::Result<()> { async_std::task::block_on(async {
-//! use tide::prelude::*;
 //! let mut app = tide::new();
 //! app.at("/").get(|_| async { Ok("hello!") });
 //!