Prep webmaker.org archive as old.webmaker.org

[xmatthewx]

As discussed, archiving webmaker.org as old.webmaker.org can reduce the risk and comms hassles with the new site launch.

What's required?

• add subdomain to SSL certificate
• add simple notice "This Webmaker site archive will be shutdown on [date]." 3-4 months post launch.
• consider impact on login, password resets, etc for thimble, makes export etc

[jbuck]

There's probably a bunch of configuration work we need to do to make everything work on the new domain but we can run old.wm.o side-by-side to test changes.