Update/align claim on website, github, mastodon...

[acka47]

Reportedby @Phu2 on Mastodon: https://openbiblio.social/@phu/111549855949294314

On Mastodon and website it reads:

Dateninfrastruktur für Bibliotheken

On GitHub:

Linking Open Bibliographic Data

We should

1. align these,
2. include archives, museums and research as users,
3. check whether it needs to be updated elsewhere.