Document which branches must be replicated to replicate the account data

Change-Id: I2c9dc06927cd8e9e541eb032829029bdfac8db6e
Signed-off-by: Edwin Kempin <ekempin@google.com>
(cherry picked from commit 93ab1609a4ba32e9466ff0649317b84a211285ad)

src/main/resources/Documentation/about.md

diff --git a/src/main/resources/Documentation/about.md b/src/main/resources/Documentation/about.md
index dd9cea5..69a371b 100644
--- a/src/main/resources/Documentation/about.md
+++ b/src/main/resources/Documentation/about.md
@@ -16,3 +16,15 @@
 local path as replication target. This makes e.g. sense if a network
 share is mounted to which the repositories should be replicated.
 
+Replication of account data (NoteDb)
+------------------------------------
+
+To replicate the account data in NoteDb the following branches from the
+`All-Users` repository must be replicated:
+
+* `refs/users/*` (user branches)
+* `refs/meta/external-ids` (external IDs)
+* `refs/starred-changes/*` (star labels)
+* `refs/sequences/accounts` (account sequence numbers, not needed for Gerrit
+  slaves)
+