Update chatbot documentation

Summary:
Remove's PhabricatorBotDifferentialNotificationHandler documentation and adds in:
PhabricatorBotFeedNotificationHandler
PhabricatorBotSymbolHandler
PhabricatorBotMacroHandler

Should have been included in D9477

Test Plan: Read it..?

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9479

Author: Guy Warner

src/docs/tech/chatbot.diviner

@@ -44,11 +44,16 @@ the bot. These are the default handlers available:
   - @{class:PhabricatorBotObjectNameHandler} This handler looks for users
     mentioning Phabricator objects like "T123" and "D345" in chat, looks them
     up, and says their name with a link to the object. Requires conduit.
-  - @{class:PhabricatorBotDifferentialNotificationHandler} This handler posts
+  - @{class:PhabricatorBotFeedNotificationHandler} This handler posts
     notifications about changes to revisions to the channels listed in
     ##notification.channels##.
   - @{class:PhabricatorBotLogHandler} This handler records chatlogs which can
     be browsed in the Phabricator web interface.
+  - @{class:PhabricatorBotSymbolHandler} This handler posts responses to lookups
+    for symbols in Diffusion
+  - @{class:PhabricatorBotMacroHandler} This handler looks for users mentioning
+    macros, if found will convert image to ASCII and output in chat. Configure
+    with ##macro.size## and ##macro.aspect##
 
 You can also write your own handlers, by extending
 @{class:PhabricatorBotHandler}.