Add Kiwix container installer and metadata

Introduce a complete Kiwix LXC installer: ct/kiwix.sh (container template) and install/kiwix-install.sh (in-container install). The installer installs kiwix-tools from the Kiwix PPA, creates a systemd kiwix-serve service to serve /data/*.zim on port 8080, records the package version in /root/.kiwix, and includes an update_script to upgrade kiwix-tools. The container template validates a provided ZIM_DATA directory, configures a bind mount (using ID-mapped mounts if available), sets container options, and prints the service URL. Also add json/kiwix.json catalog metadata with usage notes (including ZIM_DATA usage and file permission guidance).

install/kiwix-install.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+# Copyright (c) 2021-2026 community-scripts ORG
+# Author: tewalds
+# License: MIT | https://github.com/community-scripts/ProxmoxVE/raw/main/LICENSE
+# Source: https://github.com/kiwix/kiwix-tools
+
+source /dev/stdin <<<"$FUNCTIONS_FILE_PATH"
+color
+verb_ip6
+catch_errors
+setting_up_container
+network_check
+update_os
+
+msg_info "Installing Dependencies"
+$STD apt install -y software-properties-common
+msg_ok "Installed Dependencies"
+
+msg_info "Adding Kiwix PPA"
+add-apt-repository -y ppa:kiwixteam/release >>"$(get_active_logfile)" 2>&1
+$STD apt update
+msg_ok "Added Kiwix PPA"
+
+msg_info "Installing Kiwix-Tools"
+$STD apt install -y kiwix-tools
+RELEASE=$(dpkg -s kiwix-tools 2>/dev/null | awk '/^Version:/{print $2}')
+echo "${RELEASE}" >/root/.kiwix
+msg_ok "Installed Kiwix-Tools ${RELEASE}"
+
+mkdir -p /data
+
+msg_info "Creating Service"
+cat <<'EOF' >/etc/systemd/system/kiwix-serve.service
+[Unit]
+Description=Kiwix ZIM Server
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/bin/sh -c 'exec /usr/bin/kiwix-serve --port 8080 /data/*.zim'
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target
+EOF
+systemctl enable kiwix-serve
+msg_ok "Created Service"
+
+motd_ssh
+customize
+cleanup_lxc