fix typo

Author: omahs

README.md

@@ -63,7 +63,7 @@ fn main() {
 
 # Standard library
 
-It is now possible to easily replicate this crate's functionality in Rust's standard library with [`std::sync::OnceLock`](https://doc.rust-lang.org/std/sync/struct.OnceLock.html). The example above could be also be written as:
+It is now possible to easily replicate this crate's functionality in Rust's standard library with [`std::sync::OnceLock`](https://doc.rust-lang.org/std/sync/struct.OnceLock.html). The example above could also be written as:
 
 ```rust
 use std::collections::HashMap;