add ruyadorno to calendar maintainers (#792)

Author: ruyadorno

README.md

@@ -85,5 +85,6 @@ This list should be reviewed and pruned annually (at minimum). The calendar has
 - [@mcollina](https://github.com/mcollina) - **Matteo Collina**
 - [@mhdawson](https://github.com/mhdawson) - **Michael Dawson**
 - [@MylesBorins](https://github.com/MylesBorins) - **Myles Borins**
+- [@ruyadorno](https://github.com/ruyadorno) - **Ruy Adorno**
 - [@ryanmurakami](https://github.com/ryanmurakami) - **Ryan Lewis**
 - [@trott](https://github.com/trott) - **Rich Trott**