Enable header permalinks

Enable header permalinks

Use the toc extension "permalinks" option to enable header permalinks.

Bug-AGL: SPEC-4927

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: If06b1172d1dd295cc22e60bdf89f301b0c880ae6
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/documentation/+/29285
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
Tested-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
(cherry picked from commit ae87e29eeaeadd67a449f8827aa8d4adbe2076b5)
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/documentation/+/29358