Merge rayon-rs#660

660: docs: fix "double wording" r=cuviper a=janriemer

"to to" -> "to"

Co-authored-by: ฅ^•ﻌ•^ฅ <janriemer@users.noreply.github.com>

Author: bors[bot]

README.md

@@ -74,7 +74,7 @@ as:
 rayon = "1.0"
 ```
 
-and then add the following to to your `lib.rs`:
+and then add the following to your `lib.rs`:
 
 ```rust
 extern crate rayon;