Document that fallback code owners are not suggested

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: Ib82644544dfad38711ec3eb2fafab13ff716c59f

resources/Documentation/rest-api.md

diff --git a/resources/Documentation/rest-api.md b/resources/Documentation/rest-api.md
index 058d1ff..80a58d9 100644
--- a/resources/Documentation/rest-api.md
+++ b/resources/Documentation/rest-api.md
@@ -342,6 +342,7 @@
 * are referenced by an email with a disallowed domain (see
   [allowedEmailDomain configuration](config.html#pluginCodeOwnersAllowedEmailDomain))
 * do not have read access to the branch
+* [fallback code owners](config.html#pluginCodeOwnersFallbackCodeOwners)
 
 are omitted from the result.