sysadm/server-architecture: add work in progress markers

sysadm/server-architecture/backups/howto-access-backups.rst

+.. _server_architecture_backups_access:
+
 How to access backups
 =====================
+
+.. todo::
+   This page is a work in progress. Please refer to the `existing documentation
+   <https://intranet.softwareheritage.org/wiki/Backups>`_.

sysadm/server-architecture/backups/reference-infrastructure.rst

+.. _server_architecture_backups_infrastructure:
+
 Backup infrastructure
 =====================
+
+.. todo::
+   This page is a work in progress. Please refer to the `existing documentation
+   <https://intranet.softwareheritage.org/wiki/Backups>`_.

sysadm/server-architecture/howto-install-new-physical-server.rst

+.. _server_architecture_install_physical:
+
 How to install a new physical server
 ====================================
+
+.. todo::
+   This page is a work in progress.

sysadm/server-architecture/howto-provision-new-vm.rst

+.. _server_architecture_provision_vm:
+
 How to provision a new VM
 =========================
+
+.. todo::
+   This page is a work in progress. Please refer to the `existing documentation`_.
+
+.. _existing documentation: https://forge.softwareheritage.org/source/swh-sysadmin-provisioning/browse/master/proxmox/terraform/

sysadm/server-architecture/howto-search-inventory.rst

+.. _server_architecture_inventory_search:
+
 How to search the inventory
 ===========================
+
+.. todo::
+   This page is a work in progress.

sysadm/server-architecture/howto-upgrade-machine.rst

+.. _server_architecture_upgrade:
+
 How to upgrade a machine
 ========================
+
+.. todo::
+   This page is a work in progress.

sysadm/server-architecture/reference-baseline-hardware.rst

+.. _server_architecture_hardware_baseline:
+
 Reference: Baseline for hardware purchases
 ==========================================
+
+.. todo::
+   This page is a work in progress.

sysadm/server-architecture/reference-inventory.rst

+.. _server_architecture_inventory:
+
 Reference: Inventory of machines
 ================================
+
+.. todo::
+   This page is a work in progress. If you're connected to the Software Heritage
+   VPN, please have a look at our `netbox instance`_.
+
+.. _netbox instance: https://inventory.internal.softwareheritage.org/