man pages: use standard NAME format

As per man(7):

    The only mandatory heading is NAME, which should
    be the first section and be followed on the next
    line by a one-line description of the program:

        .SH NAME
        item \- description

    It is extremely important that this format is followed,
    and that there is a backslash before the single dash
    which follows the item name. This syntax is used by the
    mandb(8) program to create a database of short
    descriptions for the whatis(1) and apropos(1) commands.

Furthermore (lexgrog(1)):

    When using the traditional man macro set, a correct NAME
    section looks something like this:

        .SH NAME
        foo \- program to do something

    Some manual pagers require the ‘\-’ to be exactly as shown;
    mandb is more tolerant, but for compatibility with other
    systems it is nevertheless a good idea to retain the
    backslash.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>