This NIP is not yet in main. Here is an overview of PRs referencing this NIP. 
NIP-95 (FROST signature scheme for signing Nostr events) OPEN @zmeyer44
NIP-95 Revisit CLOSED @arthurfranca
RFC: Extending Nostr to support x.509 certificates CLOSED @djschnei21
NIP-95 - Storage and Shared File OPEN @frbitten