Add missing zfs-2.1.13 changelog link

Signed-off-by: Tony Hutter <hutter2@llnl.gov>

Author: tonyhutter

index.html

@@ -41,6 +41,7 @@
 			<a href="https://github.com/openzfs/zfs/releases/tag/zfs-2.1.10">v2.1.10</a>
 			<a href="https://github.com/openzfs/zfs/releases/tag/zfs-2.1.11">v2.1.11</a>
 			<a href="https://github.com/openzfs/zfs/releases/tag/zfs-2.1.12">v2.1.12</a>
+			<a href="https://github.com/openzfs/zfs/releases/tag/zfs-2.1.13">v2.1.13</a>
 		</td>
 		<td> <a href="https://openzfs.github.io/openzfs-docs/man/index.html">2.1.13</a> </td>
 		<td> Sep 27 2023 </td>