Allow to add individual event pages

[morchickit]

This is for user story 11 - (issue #95 ) : Some Open Data Day orginisers will need their own event name (maybe something like opendataday.org/year/location). I assume that since this is a github pages site, this should be easy.
We need to -

1. Allow users to add their event page to the site in an easy manner.
2. Document how to add the event page.
3. Have a page name "events" that is a table of contents to all the events that were added.

[tlacoyodefrijol]

@morchickit is this issue covered by the Map we have right now?