Fix typo in README.md

Author: surjikal

README.md

@@ -5,5 +5,5 @@ Hub page for the full readme on how to use the Docker image and for information
 regarding contributing and issues.
 
 The full readme is generated over in [docker-library/docs](https://github.com/docker-library/docs),
-specificially in [docker-library/docs/nginx](https://github.com/docker-library/docs/tree/master/nginx).
+specifically in [docker-library/docs/nginx](https://github.com/docker-library/docs/tree/master/nginx).