included OpenAPI spec file

README.md

@@ -2,6 +2,8 @@
 
 All of this has been compiled and tested by hand in Jan of 2018, prior to this most of the information was spread across the internet in various posts and not available in a cohesive
 single place.
+
+[OpenAPI 3.0 specification file for the NHL API](https://github.com/erunion/sport-api-specifications/tree/master/nhl) thanks to @[erunion](https://github.com/erunion)
 ### Teams
 
 `GET https://statsapi.web.nhl.com/api/v1/teams` Returns a list of data about
@@ -972,4 +974,4 @@ Ex:
     "ranks" : { }
   } ]
 }
-```
+```