Documentation: format full commands in typewriter font

Documentation: format full commands in typewriter font

Use `code snippet` style instead of 'emphasis' for `git cmd ...`
according to the following rules:

* The SYNOPSIS sections are left untouched.

* If the intent is that the user type the command exactly as given, it
  is `code`.
  If the user is only loosely referred to a command and/or option, it
  remains 'emphasised'.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>