@module takes an arg, to give name (re #5)

@module and @memberOf together are enough to force a tree-like structure
to the document.  However @module requires a `ctx` object to get a
sensible name (from ctx.name).  For the `main` module (and in some other
cases, like weird coding patters, evals, and anywhere else the regex
pased detection in `dox` fails (Moz code like 'const','let', others),
that name will be non-existent or wrong.

Here:

  @module modname

will specify a module name to use.