Add download and documentation links for 2.15.13

Change-Id: I15539500e4a7ba3adad946dc5f5c19d39e6f79ba
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index 89e4e17..468288c 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -6,7 +6,8 @@
 toc: true
 ---
 
-Download: **[2.15.12](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.12.war)**
+Download: **[2.15.13](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.13.war)**
+| [2.15.12](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.12.war)
 | [2.15.11](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.11.war)
 | [2.15.10](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.10.war)
 | [2.15.9](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.9.war)
@@ -20,7 +21,8 @@
 | [2.15.1](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.1.war)
 | [2.15](https://gerrit-releases.storage.googleapis.com/gerrit-2.15.war)
 
-Documentation: **[2.15.12](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.12/index.html)**
+Documentation: **[2.15.13](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.13/index.html)**
+| [2.15.12](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.12/index.html)
 | [2.15.11](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.11/index.html)
 | [2.15.10](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.10/index.html)
 | [2.15.9](https://gerrit-documentation.storage.googleapis.com/Documentation/2.15.9/index.html)