rpm-ostree: add page (#8277)

* rpm-ostree: add page

* rpm-ostree: amend example description wording

Co-authored-by: CleanMachine1 <78213164+CleanMachine1@users.noreply.github.com>

* rpm-ostree: fix tldr variable syntax, drop install apply-live example

* Update pages/linux/rpm-ostree.md

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

* Update pages/linux/rpm-ostree.md

Co-authored-by: marchersimon <50295997+marchersimon@users.noreply.github.com>

* Update pages/linux/rpm-ostree.md

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

Co-authored-by: CleanMachine1 <78213164+CleanMachine1@users.noreply.github.com>
Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>
Co-authored-by: marchersimon <50295997+marchersimon@users.noreply.github.com>

pages/linux/rpm-ostree.md

@@ -0,0 +1,25 @@
+# rpm-ostree
+
+> A hybrid image/package system.
+> Manage ostree deployments, package layers, filesystem overlays, and boot configuration.
+> More information: <https://coreos.github.io/rpm-ostree/administrator-handbook/>.
+
+- Show rpm-ostree deployments in the order they will appear in the bootloader:
+
+`rpm-ostree status`
+
+- Show packages which are outdated and can be updated:
+
+`rpm-ostree upgrade --preview`
+
+- Prepare a new ostree deployment with upgraded packages and reboot into it:
+
+`rpm-ostree upgrade --reboot`
+
+- Reboot into the previous ostree deployment:
+
+`rpm-ostree rollback --reboot`
+
+- Install a package into a new ostree deployment and reboot into it:
+
+`rpm-ostree install {{package}} --reboot`