Draft charter

Here is a draft of a charter:

   https://w3c.github.io/sparql-12/charter.html

It is taken from the W3C CG-template with the {TBD} sections filled out.
http://w3c.github.io/cg-charter/CGCharter.html

source:
   https://github.com/w3c/sparql-12/docs/charter.html

issue:
   https://github.com/w3c/sparql-12/issues/2
or the mailing list.

There is an issue for the charter on github. It is help if CG 
participants who agree indicate with a +1 reaction.

Of note is the section on technical work taken from the CG-template:

"""
If the group uses GitHub, all technical work will occur in its GitHub 
repositories (and not in mailing list discussions).
"""

I don't take that to stop discussions on public list, realistically, 
they will happen, but the place of record is github.

There is a choice point for the CG here: github OR mailing list as the 
record. Given features evolving separately, I see the GH issues with its 
forum format makes long term discussions easier.

     Andy