[lmi] MST: adding paragraph breaks to {{ProductDescription}}

[Greg Chicares]

Vadim--Three ledger types already use {{ProductDescription}}, and the
fourth, as you noted inline, should use it too. The (proprietary)
contents generally look like this today:

std::string ProductDescription =
  "This is the XYZZY product."
  "" // There should be a paragraph break here.
  "It has several death benefit options, viz. ..."
  "" // There should be a paragraph break here.
  "Here's another blurb that wants to be a separate paragraph."
  ;

C++ doesn't use the empty string as a paragraph break, of course, but
I thought maybe I could accomplish that by writing "\n" instead. Alas,
that has no effect on the generated PDF. Would it be in good taste to
make embedded newlines serve that purpose? Or do we really need:

std::string ProductDescription0 = "This is the XYZZY product.";
std::string ProductDescription1 = "It has several death benefit options."

and so on, with one variable per paragraph?