Missing SIGs at ACL 2025

https://aclanthology.org/volumes/2025.sigtyp-1/ should be under SIGTYP as the SIG (not just the venue)

https://aclanthology.org/volumes/2024.bionlp-1/ should be SIGBIOMED? [BioNLP](https://aclanthology.org/venues/bionlp/) appears to be an annual event, but [SIGBIOMED](https://aclanthology.org/sigs/sigbiomed/) is missing many years.

https://aclanthology.org/volumes/2025.bsnlp-1/ should be SIGSLAV? The [BSNLP](https://aclanthology.org/venues/bsnlp/) series includes 2023 and 2025, which are missing from the [SIGSLAV](https://aclanthology.org/sigs/sigslav/) page.

This is just checking a few of the workshops; there may be more missing SIGs.

It is confusing to link to SIGs from the homepage if their pages are not populated consistently. Perhaps we should remove those and have a page that lists workshop venue names instead.