Merge pull request rms-open-letter#803 from vkatsikaros/patch-1

Update index.md

Author: neilmcgovern

index.md

@@ -867,6 +867,7 @@ Signed,
 - Trolli Schmittlauch
 - Tuna Ilgaz
 - Ujjwal Sharma (Node.js Core Collaborator, TC39, Igalia)
+- Vangelis Katsikaros
 - Victor Hugo Soliz Kuncar
 - Victoria "tdfischer" Fierce (Former KDE Multimedia and Phonon-GStreamer maintainer)
 - Viktoriia Leontieva (Product Designer at GitHub)