Fix documentation for 'exclude-groups' parameter of suggest reviewer REST endpoint

The current documentation says that groups can be excluded by 'e=f'. I
think this translates to 'exclude-groups=false' which would actually
include groups.

Change-Id: I1ee44c6c1dd3d1a1afcf13714f9b71319788ac32
Signed-off-by: Edwin Kempin <ekempin@google.com>
diff --git a/Documentation/rest-api-changes.txt b/Documentation/rest-api-changes.txt
index 56114ce..46ca808 100644
--- a/Documentation/rest-api-changes.txt
+++ b/Documentation/rest-api-changes.txt
@@ -2987,7 +2987,12 @@
 Suggest the reviewers for a given query `q` and result limit `n`. If result
 limit is not passed, then the default 10 is used.
 
-Groups can be excluded from the results by specifying 'e=f'.
+Groups can be excluded from the results by specifying the 'exclude-groups'
+request parameter:
+
+--
+'GET /changes/link:#change-id[\{change-id\}]/suggest_reviewers?q=J&n=5&exclude-groups'
+--
 
 As result a list of link:#suggested-reviewer-info[SuggestedReviewerInfo] entries is returned.