fix typo in release history table

Author: MikeRalphson

versions/3.1.0.md

@@ -3424,7 +3424,7 @@ Two examples of this:
 
 Version | Date | Notes
 --- | --- | ---
-3.1.0-rc0 | 2020-10-08 | rc1 of the 3.1 specification
+3.1.0-rc1 | 2020-10-08 | rc1 of the 3.1 specification
 3.1.0-rc0 | 2020-06-18 | rc0 of the 3.1 specification
 3.0.3 | 2020-02-20 | Patch release of the OpenAPI Specification 3.0.3
 3.0.2 | 2018-10-08 | Patch release of the OpenAPI Specification 3.0.2