Update / Refresh Acknowledgements page

[ahouseholder]

It's been a while since we updated docs/about/acknowledgements.md, and we've added a few significant contributors since then.

[sei-renae]

Notably, "authors" is not a defined set on docs/about/acknowledgements.md. $\set {authors} = \set {pdfPaperAuthors} ?$

[ahouseholder]

Yeah, the wording of that page stems from the PDFs

However, also note that the author list changed over the different versions. So we probably ought to have something like:

SSVC began as a series of papers before we created this site. Original authors listed below:

Towards Improving... https://github.com/CERTCC/SSVC/blob/main/pdfs/2018_019_001_538372.pdf
SSVC v1 https://github.com/CERTCC/SSVC/blob/main/pdfs/2019_019_001_636391.pdf
SSVC v1.1 https://github.com/CERTCC/SSVC/blob/main/pdfs/weis20-final6.pdf
SSVC v2 https://github.com/CERTCC/SSVC/blob/main/pdfs/2021_019_001_653461.pdf
SSVC v2.1 https://github.com/CERTCC/SSVC/blob/main/pdfs/ssvc_2_1_draft.pdf

...then current acks and the rest