[open-data-manual] Moved opendatamanual repo to github

[Rufus Pollock]

Hi All,

As per previous discussions we have now moved Open Data Manual
'official' repo to github:

<https://github.com/okfn/opendatamanual>

I note that the previous repo of that name on github had to be trashed
and rebuilt because it had been built of a sync from the mercurial
repo that was no longer working (so if you had followed/forked you'll
have to re-follow / re-fork -- apologies!)

Issues will also relocate there. For the wiki we plan to plan to just
put on wiki.okfn.org for present (esp as github wiki may be used to
allow easy editing):

<http://wiki.okfn.org/Open_Data_Manual>

Rufus