Update docs/concurrency_design.md

Co-authored-by: Tomás Grüner <47506558+MegaRedHand@users.noreply.github.com>

Author: Arkenan

docs/concurrency_design.md

@@ -66,7 +66,7 @@ Improvements:
 ### Other issues
 
 - States aren't ever stored in the DB. This is not a concurrency issue, but we should fix it.
-- Low priority, but we should evaluate dropping the Subscriber genServer and broadway, and have one task per message under a supervisor.
+- Low priority, but we should evaluate dropping the Subscriber GenServer and Broadway, and have one task per message under a supervisor.
 
 ## State Diagram