ostree: replace minimal by fixedfunction

Rename `minimal` to `fixedfunction` to reflects the "Fixed function device
scenario" from Apertis Platform Technical Vision.

Also replace references to `18.06` and `18.12` releases by `v2022` which
is the first release version providing `fixedfunction` images.

Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>

content/guides/ostree.md

 +++
 date = "2019-01-08"
+lastmod = "2021-09-15"
 weight = 100
 toc = true
 
@@ -71,9 +72,9 @@ to use it for the system upgrade.
 ### Manual offline update
 
 It is possible to update the system manually from local file with CLI,
-for instance to update SabreLite device manually to 18.12 release:
+for instance to update SabreLite device manually to v2022dev3 release:
 
-    updatectl --apply-static-delta apertis_ostree_18.12-minimal-armhf-mx6qsabrelite_18.12.0.delta
+    updatectl --apply-static-delta apertis_ostree_v2022dev3-fixedfunction-armhf-uboot_v2022dev3.0.delta
 
 ## Automatic rollback
 
@@ -108,18 +109,18 @@ label is attached to the commit to use on next boot.
 
     $ sudo ostree admin status
       apertis 8d77e30a3ae56f0b0bac2e92dfef17869a1764e65936e2c32cb4791330601836.0 (pending)
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
     * apertis 398824a16a766149a9c025311745472739f85d310fd6b1346456050dc112671a.0
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
 
 After the reboot, the `(rollback)` label is attached to the commit
 that was in use before the update.
 
     $ sudo ostree admin status
     * apertis 8d77e30a3ae56f0b0bac2e92dfef17869a1764e65936e2c32cb4791330601836.0
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
       apertis 398824a16a766149a9c025311745472739f85d310fd6b1346456050dc112671a.0 (rollback)
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
 
 # Switching to the previous release
 
@@ -135,9 +136,9 @@ And after reboot, the status is:
 
     $ sudo ostree admin status
     * apertis 398824a16a766149a9c025311745472739f85d310fd6b1346456050dc112671a.1
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
       apertis 8d77e30a3ae56f0b0bac2e92dfef17869a1764e65936e2c32cb4791330601836.0 (rollback)
-        origin refspec: origin:apertis/18.06/amd64-uefi/minimal
+        origin refspec: origin:apertis/v2022dev3/amd64-uefi/fixedfunction
 
 Note how the new commit labelled rollback is now the commit
 corresponding to the latest update.