docs(shell): mention "&" for piping with powershell #20459

New behaviour since PR #19438

runtime/doc/various.txt

@@ -259,6 +259,10 @@ g8			Print the hex values of the bytes used in the
 			or stderr, the streams are closed immediately. |E5677|
 			Use |jobstart()| instead. >
 				:call jobstart('foo', {'detach':1})
+<
+			For powershell, chaining a stringed executable path
+			requires using the call operator (&). >
+				:!Write-Output "1`n2" | & "C:\Windows\System32\sort.exe" /r
 <
 							*E34*
 			Any "!" in {cmd} is replaced with the previous