Add Codeberg to signatories

Author: marcprux

src/data/signatures.yaml

@@ -16,6 +16,9 @@
 - organization: "Chaos Computer Club"
   url: "ccc.de"
   poc: "Elina Eickstädt <presse@ccc.de>"
+- organization: "Codeberg"
+  url: "codeberg.org"
+  poc: "Gusted <contact@codeberg.org>"
 - organization: "Cryptee"
   url: "crypt.ee"
   poc: "John Ozbay <hello@johnozbay.com>"