Newsletter 3: Add discussion links (rust-gamedev#35)

Author: ozkriff

_drafts/newsletter-004.md

@@ -83,12 +83,9 @@ Feel free to send PRs about your own projects!
 Also, subscribe to [@rust_gamedev on Twitter][@rust_gamedev]
 or [/r/rust_gamedev subreddit][/r/rust_gamedev] if you want to receive fresh news!
 
-<!--
-TODO: Add real links and un-comment once this post is published
 **Discussions of this post**:
-[/r/rust](TODO),
-[twitter](TODO).
--->
+[/r/rust](https://reddit.com/r/rust/comments/dt3uc9/this_month_in_rust_gamedev_3_october_2019),
+[twitter](https://twitter.com/rust_gamedev/status/1192539926161702913).
 
 [/r/rust_gamedev]: https://reddit.com/r/rust_gamedev
 [@rust_gamedev]: https://twitter.com/rust_gamedev