runtime(doc): warn users about potentially risky hotkey

Also, mention that CTRL-SHIFT-V might be mapped to paste text, similar
to the note about CTRL-V.

References:
https://gitlab.gnome.org/GNOME/gnome-terminal/-/blob/2d7e9d78c9631be63b6b381f6966cb8808865ffb/src/org.gnome.Terminal.gschema.xml#L395-398
https://gitlab.gnome.org/chergert/ptyxis/-/blob/8942adde5b98c82c85238851743b371a034a1c1b/src/org.gnome.Ptyxis.gschema.xml.in#L529-L533

closes: #16816

Signed-off-by: David Mandelberg <david@mandelberg.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/cmdline.txt b/runtime/doc/cmdline.txt
index a50fc74..b8c6c17 100644
--- a/runtime/doc/cmdline.txt
+++ b/runtime/doc/cmdline.txt
@@ -1,4 +1,4 @@
-*cmdline.txt*   For Vim version 9.1.  Last change: 2024 Oct 05
+*cmdline.txt*   For Vim version 9.1.  Last change: 2025 Mar 08
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -88,6 +88,10 @@
 CTRL-SHIFT-Q	Works just like CTRL-V, unless |modifyOtherKeys| is active,
 		then it inserts the Escape sequence for a key with modifiers.
 		In the GUI the |key-notation| is inserted without simplifying.
+		Note: When CTRL-SHIFT-V is intercepted by your system
+		(e.g., to paste text) you can often use CTRL-SHIFT-Q instead.
+		However, in some terminals (e.g. Gnome Terminal), CTRL-SHIFT-Q
+		quits the terminal without confirmation.
 
 							*c_<Left>* *c_Left*
 <Left>		cursor left.  See 'wildmenu' for behavior during wildmenu
diff --git a/runtime/doc/insert.txt b/runtime/doc/insert.txt
index 71ba061..0766838 100644
--- a/runtime/doc/insert.txt
+++ b/runtime/doc/insert.txt
@@ -1,4 +1,4 @@
-*insert.txt*    For Vim version 9.1.  Last change: 2025 Feb 14
+*insert.txt*    For Vim version 9.1.  Last change: 2025 Mar 08
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -222,6 +222,10 @@
 CTRL-SHIFT-V				*i_CTRL-SHIFT-V* *i_CTRL-SHIFT-Q*
 CTRL-SHIFT-Q	Works just like CTRL-V, unless |modifyOtherKeys| is active,
 		then it inserts the Escape sequence for a key with modifiers.
+		Note: When CTRL-SHIFT-V is intercepted by your system (e.g.,
+		to paste text) you can often use CTRL-SHIFT-Q instead.
+		However, in some terminals (e.g. Gnome Terminal), CTRL-SHIFT-Q
+		quits the terminal without confirmation.
 
 CTRL-X		Enter CTRL-X mode.  This is a sub-mode where commands can
 		be given to complete words or scroll the window.  See