doc: Add subsections to 'Invoking guix build'.

* doc/guix.texi (Invoking guix build): Add example.  Shuffle options in
the new subsections below.
(Common Build Options, Additional Build Options): New nodes.
(Invoking guix archive): Refer to "Common Build Options".
(Invoking guix environment): Likewise.
(Invoking guix system): Likewise.

fixlet