Fill out mailing list operator spec (#26)

Per discussion with @Emzy in Slack.
See https://bisq.slack.com/archives/C7P9HQC56/p1509457636000678

mailing-list-operator.adoc

@@ -7,22 +7,30 @@ Issue: https://github.com/bisq-network/roles/issues/26[bisq-network/roles#26]
 
 toc::[]
 
-NOTE: This specification is just a placeholder for now. See the linked issue above for status.
-
 == Purpose
 
+To maintain a mailing list suitable for discussions about Bisq development and other forms of contribution.
 
 == Motivation
 
+The old https://groups.google.com/forum/#!forum/bitsquare[Bitsquare Google Group] has fallen out of use. This is partially due to the fact that we set up a Mailchimp-based newsletter later on in the project, and the purpose of the Google Group became unclear afterwards. Our motivation here is to replace the Google Group with a our own GNU Mailman instance at https://lists.bisq.network, and to use it to manage a clearly-defined _contributors_ mailing list. Mailman is well-understood and well-liked by free software contributors, and so we assume it will be a good fit for Bisq contributors going forward. The Mailchimp-based newsletter will stick around, as it is an idiomatic way to stay in touch with Bisq's not necessarily technical users.
 
 == Privileges
 
+The operator will have administrative access to the Mailman server at https://lists.bisq.network, as well as administrative access to the infrastructure that hosts it.
 
 == General Requirements
 
-=== Bonding
-The operator MUST post a bond of **TBD** BSQ to assume this role.
+The operator MUST:
 
+ - post a bond of **TBD** BSQ to assume this role
+ - maintain this role specification document
 
 == Special Requirements
 
+The operator MUST:
+
+ - keep the Mailman installation up and running
+ - keep the Mailman installation up to date with latest patches
+ - respond promptly to any questions / requests in the #lists Slack channel (recommendation: set your Slack notification preferences for that channel to be notified on "all new messages" so you don’t miss anything)
+ - acknowledge / respond promptly to any issues submitted to the https://github.com/bisq-network/lists[bisq-network/lists] GitHub repository