Update contributing link in README.md

Author: kiron1

README.md

@@ -66,7 +66,7 @@ look at some of these issues:
 - [Issues labeled "good first issue"][good-first-issue]
 - [Issues labeled "help wanted"][help-wanted]
 
-[contributing]: https://github.com/http-rs/async-h1/blob/master.github/CONTRIBUTING.md
+[contributing]: https://github.com/http-rs/async-h1/blob/master/.github/CONTRIBUTING.md
 [good-first-issue]: https://github.com/http-rs/async-h1/labels/good%20first%20issue
 [help-wanted]: https://github.com/http-rs/async-h1/labels/help%20wanted