steamos-chroot: add page (#15449)

Author: Managor

pages/linux/steamos-chroot.md

@@ -0,0 +1,16 @@
+# steamos-chroot
+
+> Switch root directory in a SteamOS environment.
+> More information: <https://gitlab.com/users/evlaV/projects>.
+
+- Switch to the other A/B partition:
+
+`steamos-chroot --partset other`
+
+- Switch to a partition on another drive:
+
+`steamos-chroot --disk {{/dev/sdX}} --partset {{A|B}}`
+
+- Display help:
+
+`steamos-chroot --help`