Update README.md

(cherry picked from commit 95eed8b)

Author: Bilogweb3

rayon-core/src/sleep/README.md

@@ -139,7 +139,7 @@ The full protocol for a thread to fall asleep is as follows:
   * Checks the JEC to see that it has not changed from `final_value`.
     * If it has, then the thread goes back to searching for work. We reset to
       just before we got sleepy, so that we will do one more search
-      before attending to sleep again (rather than searching for many rounds).
+      before attempting to sleep again (rather than searching for many rounds).
   * Increments the number of sleeping threads by 1.
 * The thread then executes a seq-cst fence operation (see below).
 * The thread then does one final check for injected jobs (see below). If any