pages/*: add backticks around I/O streams (#10436)

* as suggested in #10428
* standard input  => `stdin`
* standard output => `stdout`
* standard error  => `stderr`

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/linux/script.md

@@ -15,6 +15,6 @@
 
 `script -a {{path/to/session.out}}`
 
-- Record timing information (data is outputted to the standard error):
+- Record timing information (data is outputted to `stderr`):
 
 `script -t 2> {{path/to/timingfile}}`