Update terminology to "controlled vocabularies"

[skounis]

There is a minor inconsistency in the use of the term "controlled vocabulary" in the documentation. The correct term should be "controlled vocabularies" to reflect the use of multiple vocabularies in different contexts.

https://github.com/eu-digital-identity-wallet/eudi-doc-architecture-and-reference-framework/blob/main/docs/arf.md?plain=1#L1174

Current Text:

"To re-use the building blocks of attributes and attestations, the concept of using catalogues was introduced. Creating and maintaining controlled vocabulary, catalogue of attributes and attestation rulebooks, is essential for the development and success of the EUDI Wallet ecosystem, enabling shorter "time-to-market" and efficient implementation."

Proposed Change:

"To re-use the building blocks of attributes and attestations, the concept of using catalogues was introduced. Creating and maintaining controlled vocabularies, a catalogue of attributes, and attestation rulebooks is essential for the development and success of the EUDI Wallet ecosystem, enabling shorter 'time-to-market' and efficient implementation."

[digeorgi]

Thank you very much for your suggestion. Proposed change will be available in the next ARF version.