Because when I see "config.system.build.manual.manual" after I forgot
what it means I ask "Why do I need that second `.manual` there again?".
Doesn't happen with `config.system.build.manual.manualHTML`.
* manual: Mark commands that require root
Mark every command that requires to be run as root by prefixing them
with '#' instead of '$'.
* manual: Add note about commands that require root
