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/rmmod.md

@@ -11,7 +11,7 @@
 
 `sudo rmmod --verbose {{module_name}}`
 
-- Remove a module from the kernel and send errors to syslog instead of standard error:
+- Remove a module from the kernel and send errors to syslog instead of `stderr`:
 
 `sudo rmmod --syslog {{module_name}}`