Added a proposed mission statement to the charter

I have added a mission statement to the charter (in a separate pull request); it is, essentially, the last paragraph of the (renewed) goal section. It says:

[[[
            <p class="mission">
                The <strong>mission</strong> of the <a href="https://www.w3.org/dpub/WG/ <https://www.w3.org/dpub/WG/>">Publishing Working Group</a> is to provide the necessary technologies on the Open Web Platform to make the combination of traditional publishing and the Web complete in terms of the readers’ needs, portability, distribution, archiving, offline access, or reliable cross referencing.
  All publications—with all their specificities and traditions—should become first-class entities on the Web.
            </p>
]]]

Please comment, or simply give a thumbs up, on

https://github.com/w3c/dpubwg-charter/pull/52 <https://github.com/w3c/dpubwg-charter/pull/52>

Thanks

ivan

----
Ivan Herman, W3C
Publishing@W3C Technical Lead
Home: http://www.w3.org/People/Ivan/ <http://www.w3.org/People/Ivan/>
mobile: +31-641044153
ORCID ID: http://orcid.org/0000-0003-0782-2704 <http://orcid.org/0000-0003-0782-2704>