add etiquette link

Author: puredanger

content/about/documentary.adoc

@@ -67,6 +67,7 @@ video::Y24vK_QDLFg[youtube, width=400, height=225, title="Clojure: The Documenta
 
 * https://www.cognitect.com/blog/2008/9/24/java-next-overview[Java.next Blog Series] — Stuart Halloway's 2008 series on emerging JVM languages.
 * https://chouser.us/clojure-log/[Clojure IRC Log Archive] — Preserved archive of the original Clojure IRC channel.
+* https://clojure.org/community/etiquette[Clojure Etiquette] - derived from Rich's original post to the mailing list.
 
 == Clojure Dialects & Runtimes