Add David Thompson to list of signees. (rms-open-letter#12)

davexunit · ehashman · web-flow · commit cea5f6ed309d · 2021-03-23T11:35:33.000-07:00
Co-authored-by: Elana Hashman &lt;ehashman@users.noreply.github.com&gt;
diff --git a/index.md b/index.md
@@ -46,3 +46,4 @@ Signed,
 - Lucas Bickel
 - Colin Watson (Former Debian Technical Committee member)
 - Xavier Tilley
+- David Thompson (GNU Guile/Guix contributor, ex-FSF)
