Bringing Part 1 to ODF 1.3

[Regina Henschel <regina.henschel@libreoffice.org>]

Hi Partrick, hi all,

the part 1 is still in its base form. It should be updated.

I suggest, to add here the clarifying the license, OFFICE-2153,
which Alfred mentioned in his mail from 2019-08-13.

In addition we should note, that the type of schema language was changed.

I have no strong opinion where to put OFFICE-3821 and OFFICE-2118, into 
part 1 or into part 3 (new section or with text, that indicates a change 
in scheme).

Kind regards
Regina