explain a little more what the bot will do internally

README.md

@@ -44,6 +44,16 @@ below is an example of how this bot might work:
         > @user:host now owes $other:host $X.YY
 
 
+### mechanics
+
+- on bot start, it crawls messages of every room it's in and replays the bang commands to determine positions.
+- only one bot in the room should respond to the messages (simply to ACK that they're formatted correctly);
+- but any user can run this same bot in read-only mode, either passing it creds to the user's own account
+  or (less practically) by creating a new bot user and inviting it to the relevant rooms.
+        - this provides some redundancy and more importantly allows any of us to deploy the bot, when
+          developing, to the same environment used for prod.
+
+
 ## Development/Hacking
 
 this project is built with [cargo][cargo], the [Rust][rust] package manager. simply run: