delete digest from ig.md

Author: shawna-slh

pages/about/groups/ig.md

@@ -87,11 +87,6 @@ searching for past messages and getting a feel for the list.
 the e-mail address to send an e-mail message, which is in the next
 section.
 
-To subscribe to the email **digest** with compiled messages, send e-mail
-to <[email protected]> with "subscribe" as the subject. To
-unsubscribe from the digest, send e-mail to
-<[email protected]> with "unsubscribe" as the subject.
-
 ### Sending Messages to the Discussion List
 
 To send a message to the list, first subscribe to the list (instructions