add-hook! is advertised to be able to add multiple hooks using a
function-quoted list of functions, but add-hook! never actually
supported this. Rather than correct the implementation, I'm correcting
the documentation instead, because sharp-quoting lists betrays the
semantics of the sharp-quote. Quoted lists should still work fine
though (as documented in add-hook!'s docstring).
Close: #5843
e8c22c770b