[IMP] iot: add documentation regarding IoT updates

Would be more convenient for the support to avoid repeating the same instructions
when they need to perform a certain kind of update

content/applications/productivity/iot/config.rst

@@ -11,6 +11,6 @@ Configuration
    config/connect
    config/pos
    config/https_certificate_iot
-   config/flash_sdcard
    config/troubleshooting
    config/windows_iot
+   config/updating

content/applications/productivity/iot/config/updating.rst

@@ -0,0 +1,63 @@
+:show-content:
+:hide-page-toc:
+:show-toc:
+
+========
+Updating
+========
+
+Due to the complexity of the IoT box, the term "updating" is ambiguous as several part can be updated individually.
+
+Handlers update
+===============
+Might also be referred as "drivers update" or "interfaces update".
+
+Modify the IoT handlers (drivers and interfaces) code by syncing it with the configured server drivers code.
+
+For both Windows and Iot-box, this can be performed manually in IoT boh homepage > Handlers list > Load Handlers
+https://drive.google.com/file/d/1Y1CL4tsVD6WW2EQrKIK88R52uNO-qIP-/view?usp=sharing
+
+.. note::
+   This update is also performed automatically each time the IoT is restarted.
+   Except, if you uncheck "Automatic Drivers update" in the form view of the IoT box on the Odoo server
+
+
+Code update
+===========
+Might also be referred as "IoT Odoo update".
+
+Behind the scene, the IoT uses Odoo core to run. To update its code the steps are different.
+
+For IoT:
+IoT box homepage > Version ... update
+If the button simply show "upgrade" you can click it
+It it show "Upgrade to _xx.xx_ it will actually perform an image upgrade
+
+.. note::
+   Unlike the handlers update this one will fetch the code from Odoo github repository and NOT the configured server.
+   It means that you can benefit from the latest fix and features even if they are not deployed on your server yet
+
+.. note::
+   The code update is automatically done if the configured server version change (after an upgrade for instance)
+
+For windows:
+There is no way to individually do this, you will need to uninstall the current version then reinstall it, see windows_iot.rst
+
+
+Image update
+============
+Might also be referred as "image upgrade" or "OS update".
+
+Only for the IoT box as it does not make sense for windows IoT.
+The IoT box run a particular OS (Operating System) which have some software installed by default in order to make some features of the IoT work.
+Depending on the Odoo's version that your server uses, you might need to update your IoT box image in order to be compatible with it.
+
+In order to update your image you need to reflash the SD card
+
+TODO: merge the "Flashing the SD card" rst into this one ? In this case make so that the previous URL to the reflash page
+redirect to this title
+
+.. toctree::
+   :titlesonly:
+
+   updating/flash_sdcard

content/applications/productivity/iot/config/updating/flash_sdcard.rst

@@ -1,3 +1,5 @@
+TODO: add the thing so that previous URL for this page still work
+
 ====================
 Flashing the SD card
 ====================