Correct code-block lexers

Changing `bash` lexer to `console` because it is appropriate most of
the time. Then after a manual review, some lexer have been changed.

I used `text` each time I was unsure, and for prompt outputs.

The page `/developer/building/qubes-iso-building.rst` still need to be
reviewed (look for lines starting with `$ #`).

I'm not sure about the Windows pages, should we use
[doscon](https://pygments.org/docs/lexers/#pygments.lexers.shell.MSDOSSessionLexer)
or `powershell`?

Is there an appropriate lexer for `guid.conf` content?

**Statistics - Before**
    870 bash
      9 python
      9 c
      2 yaml

**Statistics - After**
    684 console
    111 text
     44 bash
     16 yaml
      9 systemd
      9 c
      8 python
      4 ini
      4 doscon
      2 markdown
      2 desktop
      1 xorg.conf
      1 xml+jinja
      1 xml
      1 kconfig
      1 html

This suggests that the default lexer should be `console`.

developer/debugging/safe-remote-ttys.rst

@@ -68,7 +68,7 @@ A note on serial consoles
 
 If your machine has a serial console, you may with to use that, but note that a similar split-I/O model should be used to ensure Dom0 integrity. If you use the serial console as normal (via e.g. getty on ttyX, and logging in as normal), then the machine at the end of the serial cable could compromise your machine! Ideally, you would take input from your trusted keyboard, and only send the output over the serial cable via e.g. disabling getty and using:
 
-.. code:: bash
+.. code:: console
 
       script -f /dev/ttyS0