Fix authors in the document

[rofirrim]

This was pointed by the ARC review as well.

Currently it reads "Author 1, Author 2".

Given the collaborative work here, one suggestion is to state the "RISC-V Vector C Intrinsics Technical Group".

If there is a feeling the at we want to acknowledge all those who contributed as well another suggestion is to make a list of contributors in the Preamble, or early in the document. Looking forward suggestions here.