Merge pull request rms-open-letter#1428 from cooperrc/patch-1

add Ryan C. Cooper to signatures

Author: neilmcgovern

index.md

@@ -1346,6 +1346,7 @@ identification purposes only and does not constitute endorsement.)</small>
 1. Rute Correia
 1. Ryan A. Pavlik (Collabora, Monado Co-Founder, OpenXR Spec Editor)
 1. Ryan Clark
+1. Ryan C. Cooper (@cooperrc)
 1. Ryan (DasGeek) (Host of Destination Linux, Partner of Destination Linux, LLC.)
 1. Ryan Finnie (Finnix founder; Debian; Ubuntu)
 1. Ryan Gannon