Fixed simple typo

Signed-off-by: Scott Collier <emailscottcollier@gmail.com>

docs/sources/reference/api/docker-io_api.md

@@ -330,7 +330,7 @@ Status Codes:
 
 ## Library Repository
 
-### Authorize a toke for a library
+### Authorize a token for a library
 
 `PUT /v1/repositories/(repo_name)/auth`