Clarify Unsigned Event Object type

07.md

@@ -12,7 +12,7 @@ That object must define the following methods:
 
 ```
 async window.nostr.getPublicKey(): string // returns a public key as hex
-async window.nostr.signEvent(event: Event): Event // takes an event object, adds `id`, `pubkey` and `sig` and returns it
+async window.nostr.signEvent(event: { created_at: number, kind: number, tags: string[][], content: string }): Event // takes an event object, adds `id`, `pubkey` and `sig` and returns it
 ```
 
 Aside from these two basic above, the following functions can also be implemented optionally: