grubby: add page (#12346)

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>
Co-authored-by: Lena <126529524+acuteenvy@users.noreply.github.com>

pages/linux/grubby.md

@@ -0,0 +1,16 @@
+# grubby
+
+> Tool for configuring `grub` and `zipl` bootloaders.
+> More information: <https://manned.org/man/grubby.8>.
+
+- Add kernel boot arguments to all kernel menu entries:
+
+`sudo grubby --update-kernel=ALL --args '{{quiet console=ttyS0}}'`
+
+- Remove existing arguments from the entry for the default kernel:
+
+`sudo grubby --update-kernel=DEFAULT --remove-args {{quiet}}`
+
+- List all kernel menu entries:
+
+`sudo grubby --info=ALL`