Making the site more accessible to updates from groups in the community

I'd like to propose this new HTML page. By structuring it like this, it permits groups to be able to amend their own details, and to easily see how to get new groups added.

I've created a new mailing list for group leaders to be able to post to, in order to get ideas about where to have their meeting, to discuss and suggest improvements to the NWDC site, and generally to bind the group together a little better.

Happy to discuss this further either on this PR, or via e-mail.