Add release date for v0.20.2

Viktor Lövgren · Viktor Lövgren · commit 3b2b79c87920 · 2019-10-29T12:59:21.000Z
diff --git a/notes/0.20.2.markdown b/notes/0.20.2.markdown
@@ -32,3 +32,5 @@
 [#250]: https://github.com/ovotech/fs2-kafka/pull/250
 [#251]: https://github.com/ovotech/fs2-kafka/pull/251
 [#252]: https://github.com/ovotech/fs2-kafka/pull/252
+
+Released on 2019-10-29.
