Updated _Sidebar (markdown)

_Sidebar.md

@@ -8,7 +8,7 @@
   * [openSUSE][opensuse]
   * [[Ubuntu]]
 * [[Project & Community]]
-  * [Admin Documentation][admin-docs]
+  * [[Admin Documentation]]
   * [[FAQ]]
   * [[Mailing Lists]]
   * [Releases][releases]
@@ -24,7 +24,6 @@
 [arch]: https://wiki.archlinux.org/index.php/ZFS
 [gentoo]: https://wiki.gentoo.org/wiki/ZFS
 [opensuse]: https://software.opensuse.org/package/zfs
-[admin-docs]: https://pthree.org/2012/04/17/install-zfs-on-debian-gnulinux/
 [releases]: https://github.com/zfsonlinux/zfs/releases
 [issues]: https://github.com/zfsonlinux/zfs/issues
 [roadmap]: https://github.com/zfsonlinux/zfs/milestones