Install Guide: Remove obsolete files

Remove files that are not included anywhere.

Change-Id: Ie4b8560379c69ce2269e1af2c471b73606a2f769
backport: havana
(cherry picked from commit 803f6db0953189a961cddd99f4c63ab4e07609ce)
Merge "Install Guide: Remove obsolete files" into stable/havana