align directory naming conventions

[keraron]

All instances should refer to Agent Directory as:

Agent Directory: A secure, scalable, decentralized service that holds agent records. The software allows users to publish and discover agent records across the network of decentralized, federated directories. Agent Directory provides a cryptographic trust model that ensures authenticity and provenance of each record. This component is available as open-source software.

Please refer to this component as "Agent Directory" or simply "Directory". Avoid using short forms like "dir", "DIR", or "Dir".