nip01: fix json formatting.

nips/01.md

@@ -13,6 +13,7 @@ This NIP defines the basic protocol that should be implemented by everybody. New
 Each user has a keypair. Signatures, public key and encodings are done according to the [Schnorr signatures standard for the curve `secp256k1`](https://bips.xyz/340).
 
 The single object type that exists is the `event`, which has the following format on the wire:
+
 ```
 {
   id: <32-bytes sha256 of the the serialized event data>