Add survey feedback links for courses 1 & 2.

@laurelfan and @bcjordan .. can i be railsier here? :)  it's kind of a quick hack.
I would prefer to dedupe the code (probably by making a Script#feedback_url method) so you don't have the same magic constants in 2 places (you're going to have to change them soon to add course3 anyway, right?)

Maybe also wrap the whole link in an if (feedback_url) or something too