OpenSSF WG alignment and spec purpose

[sevansdell]

Hi OpenVEX team. I am trying to share information with OpenVEX to my internal team, as part of our ongoing participation in OpenSSF. When I went to the main page: https://github.com/openvex, I didn't see two things:

1. Which OpenSSF WG the project is aligned. When I looked on the OpenSSF Vulnerability Disclosures WG page, I did find a link about an OpenVEX SIG: https://github.com/ossf/OpenVEX. It would be helpful to reference back the OpenVEX SIG in the OpenVEX documentation.
2. A one or two sentence value statement about the need OpenVEX solves in addition to VEX.

Would it be possible to add these two things to the Github please? Thanks!