Address retraction in Therapeutics

[rando2]

The fantastic scite functionality that @vincerubinetti is in the process of adding to Manubot will make it easier moving forward to catch papers that are retracted or corrected after we read and reviewed them! If you haven't seen scite before, there will be badges on the references that show how many times they've been cited, whether they tend to be cited in a positive, neutral, or negative way, and whether there have been any corrections/retractions (red ❌ ).

(Note: the exact format of this badge will change, since Vince is making it horizontal to take up less room)

Here is (so far the only!) one we need to address:

• doi:10.1016/j.eng.2020.03.007, a clinical trial of Favipiravir, was retracted

There are other papers we cite that were retracted, but for the rest, we discuss the fact that they were retracted!

[rando2]

Notifying @cgreene, who requested this issue, that it now exists :)