Feat: Include previous messages in mention/assign notifications email (#3385)

app/models/conversation.rb

@@ -147,6 +147,10 @@ class Conversation < ApplicationRecord
     inbox.inbox_type == 'Twitter' && additional_attributes['type'] == 'tweet'
   end
 
+  def recent_messages
+    messages.chat.last(5)
+  end
+
   private
 
   def execute_after_update_commit_callbacks