Update 0016_public_key_checksum.md

rfc/0016_public_key_checksum.md

@@ -20,6 +20,7 @@ https://github.com/Tortue95/Duniter_Paper_Wallet/blob/master/Duniter_Auth_Protoc
 
 A public key is to be understood as an Ed25519 public key.
 It SHOULD be represented as a Base58 which length ranges {43,44} characters.
+
 It CAN be represented as a shorter Base58 string so implementation MUST handle it.