Document that disabledBranch for project overrides the global setting

Signed-off-by: Edwin Kempin <ekempin@google.com>
Change-Id: I6fa3e915cafd4d6c50139cffe517127fdc13b82d

resources/Documentation/config.md

diff --git a/resources/Documentation/config.md b/resources/Documentation/config.md
index dc5403e..a12c144 100644
--- a/resources/Documentation/config.md
+++ b/resources/Documentation/config.md
@@ -358,6 +358,9 @@
         approvals.\
         This allows branches to opt-out of the code owners functionality.\
         Can be set multiple times.\
+        Overrides the global setting
+        [plugin.@PLUGIN@.disabledBranch](#pluginCodeOwnersDisabledBranch) in
+        `gerrit.config`.\
         By default unset.
 
 <a id="codeOwnersBackend">codeOwners.backend</a>