abroot: add page (#9608)

* abroot: add page

Closes #9606

Signed-off-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

* abroot: fix typo

The `--version` and `--help` flags don't require Superuser (sudo) privileges.

* Update abroot.md

* Update abroot.md

* Update pages/linux/abroot.md

* Change symbol to ⟺

I updated the same on docs since it has better visibility

* Update pages/linux/abroot.md

* Update pages/linux/abroot.md

* Update pages/linux/abroot.md

Signed-off-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/linux/abroot.md

@@ -0,0 +1,33 @@
+# abroot
+
+> ABRoot utility provides full immutability and atomicity by transacting between 2 root partition states (A⟺B).
+> It also allows on-demand transactions via a transactional shell.
+> More information: <https://github.com/Vanilla-OS/ABRoot>.
+
+- Output the current or future root partition state:
+
+`sudo abroot get {{present|future}}`
+
+- Enter the transactional shell in the future root partition and switch root on the next boot:
+
+`sudo abroot shell`
+
+- Execute a specific command in the transactional shell in the future root partition and switch to it on the next boot:
+
+`sudo abroot exec "{{command}}"`
+
+- Install specific packages in the host inside the transactional shell in the future root partition and switch to it on the next boot:
+
+`sudo abroot exec apt install {{package1 package2 ...}}`
+
+- Update the boot partition (for advanced users only):
+
+`sudo abroot _update-boot`
+
+- Display help:
+
+`abroot --help`
+
+- Display version:
+
+`abroot --version`