[Ubuntu] Remove docs logic from Ubuntu provisioner (#1603)

* Remove docs logic on Ubuntu

* Cleanup templates

* Fix oras-cli.sh

* Remove announcements.md

images/linux/scripts/helpers/document.sh

@@ -1,42 +0,0 @@
-#!/bin/bash
-################################################################################
-##  File:  document.sh
-##  Desc:  Helper functions for writing information to the metadata document
-################################################################################
-
-function WriteItem {
-    if [ -z "$METADATA_FILE" ]; then
-        echo "METADATA_FILE environment variable must be set to output to Metadata Document!"
-        return 1;
-    else
-        echo -e "$1" | sudo tee -a "$METADATA_FILE"
-    fi
-}
-
-function AddTitle {
-    WriteItem "# $1"
-}
-
-function AddSubTitle {
-    WriteItem "## $1"
-}
-
-function DocumentInstalledItem {
-    WriteItem "- $1"
-}
-
-function DocumentInstalledItemIndent {
-    WriteItem "  - $1"
-}
-
-function AddBlockquote {
-    WriteItem "> $1"
-}
-
-function StartCode {
-    WriteItem '```'
-}
-
-function EndCode {
-    WriteItem '```'
-}