Add version bytes section

Author: clarkmoody

bip-0084.mediawiki

@@ -51,6 +51,12 @@ To derive the P2WPKH address from the above calculated public key, we use the en
     scriptPubKey: 0 <20-byte-key-hash>
                   (0x0014{20-byte-key-hash})
 
+
+===Extended Key Version===
+
+When serializing extended keys, this scheme uses alternate version bytes. Extended public keys use <code>0x04b24746</code> to produce a "zpub" prefix, and private keys use <code>0x04b2430c</code> to produce a "zprv" prefix.
+
+
 ==Backwards Compatibility==
 
 This BIP is not backwards compatible by design as described under [#considerations]. An incompatible wallet will not discover accounts at all and the user will notice that something is wrong.