make NIP-19 encoded entities extendable.

Raw JSON

{
  "kind": 1,
  "id": "1ace64f3b2f0b64c79072c1e19a6c846f1d30e35ec19569b8d81e3ff426e853f",
  "pubkey": "e771af0b05c8e95fcdf6feb3500544d2fb1ccd384788e9f490bb3ee28e8ed66f",
  "created_at": 1775046620,
  "tags": [
    [
      "e",
      "5863db046157087b176c5d688b2e4127be285f05530243eb6e0d591402ef9d75",
      "wss://pyramid.fiatjaf.com/",
      "root",
      "7fa56f5d6962ab1e3cd424e758c3002b8665f7b0d8dcee9fe9e288d7751ac194"
    ],
    [
      "p",
      "6e468422dfb74a5738702a8823b9b28168abab8655faacb6853cd0ee15deee93"
    ],
    [
      "p",
      "7fa56f5d6962ab1e3cd424e758c3002b8665f7b0d8dcee9fe9e288d7751ac194"
    ]
  ],
  "content": "make NIP-19 encoded entities extendable.",
  "sig": "3abbb55b902b27eab8000c10f1e72de4c86a87290ce780b379f05ef5302d86d17f2022db4e6ceefd0ac9e344882e038b450b1d0354fb2b2b8170a750ada2f7d4"
}