[PATCH] docs: Do not reference non-existent "--dumb" option

[Glenn Washburn]

This appears to be a relic from GRUB legacy that used a --dumb option for
its terminal command. The proper way to do this in GRUB2 is to set the
temrinal to "dumb" via the terminfo command.

Fixes: https://savannah.gnu.org/bugs/?66302
Reported-by: Jernej Jakob <jernej.jakob+savgnu@gmail.com>
Signed-off-by: Glenn Washburn <development@efficientek.com>
---
 docs/grub.texi | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/docs/grub.texi b/docs/grub.texi
index 852567a0156a..5da3835fa45f 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -2731,11 +2731,11 @@ command.
 
 However, note that GRUB assumes that your terminal emulator is
 compatible with VT100 by default. This is true for most terminal
-emulators nowadays, but you should pass the option @option{--dumb} to
-the command if your terminal emulator is not VT100-compatible or
-implements few VT100 escape sequences. If you specify this option then
-GRUB provides you with an alternative menu interface, because the normal
-menu requires several fancy features of your terminal.
+emulators nowadays. However if your terminal emulator is not VT100-compatible
+or implements few VT100 escape sequences, you shoud tell GRUB that the
+terminal is dumb using the @command{terminfo} (@pxref{terminfo}) command.
+This will have GRUB provide you with an alternative menu interface, because
+the normal menu requires several fancy features of your terminal.
 
 
 @node Vendor power-on keys
-- 
2.34.1