Update all events to have the right links and signup info

[kirahowe]

This needs to be done in the production app. If anyone is interested in tackling this let me know and I can give you admin access to the app.

We need to:

• add all events that are currently on pitonneux.com to our app
• update signup_link for every event to go to the current sign-up strategy being used -- eventually we can deal with signups directly
• update the markdown to include all the relevant links