fix: add missing P2POrder (38383) to NDKKind enum

The NDKP2POrder class was referencing NDKKind.P2POrder but this value
wasn't defined in the enum, causing TypeDoc generation to fail.
Added P2POrder = 38383 for NIP-69 support.

Author: pablof7z

core/src/events/kinds/index.ts

@@ -153,6 +153,9 @@ export enum NDKKind {
     CashuMintAnnouncement = 38172,
     FedimintMintAnnouncement = 38173,
 
+    // NIP-69: P2P Order
+    P2POrder = 38383,
+
     HighlightSet = 39802,
     CategorizedHighlightList = NDKKind.HighlightSet, // Deprecated but left for backwards compatibility