remove pgp identity from NIP-39 temporarily

the current scheme recommends signing the *fingerprint* of the pgp key, which doesn't tie into the nostr identity
this commit temporarily undos the commit adding pgp identities until a proper fixed version is merged

just signing the npub string also would not be sufficient, and the message should indicate this is for identity verification

ideally, a link to download key material would also be included

Author: Semisol

39.md

@@ -20,7 +20,6 @@ A new optional `i` tag is introduced for `kind 0` metadata event contents in add
     ["i", "twitter:semisol_public", "1619358434134196225"],
     ["i", "mastodon:bitcoinhackers.org/@semisol", "109775066355589974"]
     ["i", "telegram:1087295469", "nostrdirectory/770"]
-    ["i", "pgp:A999B7498D1A8DC473E53C92309F635DAD1B5517", "xsFNBF2V8eEBEADmjYzGOpxEI0J7jQ1qFzlsrjF6NaBSq+UqKw..."]
   ],
   ...
 }
@@ -63,9 +62,3 @@ Identity: A Telegram user ID.
 
 Proof: A string in the format `<ref>/<id>` which points to a message published in the public channel or group with name `<ref>` and message ID `<id>`. This message should be sent by user ID `<identity>` and have the text `Verifying that I control the following Nostr public key: "<npub encoded public key>"`.
 This can be located at `https://t.me/<proof>`.
-
-### `pgp`
-
-Identity: A PGP fingerprint.
-
-Proof: PGP signature of the fingerprint used in the identity field.