Document support for unit suffixes in rules.maxSourceBytes

Change-Id: Ie1fa6e731c57325a2f8955a697a5fdac52503a73
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index 29f93b2..8c488e4 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -3143,6 +3143,8 @@
 +
 A size of 0 bytes disables rules, same as rules.enable = false.
 +
+Common unit suffixes of 'k', 'm', or 'g' are supported.
++
 Default is 128 KiB.
 
 [[rules.maxPrologDatabaseSize]]rules.maxPrologDatabaseSize::