Reorganise the events

 * Move kickstart, tech days and the competition to /events/ from /schools/.
 * Add some content about the competition to the competition page (instead of
   forwarding to the game page).
 * Remove competition content from the game page.
 * Update all the links.
 * Modify event pages to be less year specific
 * Add /events index page

Change-Id: Idc525551dbc41246c64bab72ffb641fdac234e24