[wsia] [wsrp-interfaces] getMarkup() signatures

On line 33 of page 19 in the v0.3 draft spec, I inserted a comment about
how this signature for getMarkup is broken and that fixing it essentially
produces the more general one on page 21. Any reasons to not delete this
signature?

Deleting this signature would reduce section 6 to a single set of
signatures and I would then propose rearranging it to first discuss the
signatures and then discuss how the various use cases should exploit the
exposed capabilities.