message: add doc on the to_bytes of the ExtendedAddress
diff: @@ -287,6 +287,27 @@ impl ExtendedAddr {
  }
  }
  + /// encode an `ExtendedAddr` to cbor with the extra details and `crc32`
  + ///
  + /// ```
  + /// use wallet_crypto::address::{AddrType, ExtendedAddr, SpendingData, Attributes, HDAddressPayload, Addr};
  + /// use wallet_crypto::hdwallet;
  + ///
  + /// let sk = hdwallet::generate(&[0;32]);
  + /// let pk = hdwallet::to_public(&sk);
  + ///
  + /// let hdap = HDAddressPayload::new(&[1,2,3,4,5]);
  + /// let addr_type = AddrType::ATPubKey;
  + /// let sd = SpendingData::PubKeyASD(pk.clone());
  + /// let attrs = Attributes::new_single_key(&pk, Some(hdap));
  + ///
  + /// let ea = ExtendedAddr::new(addr_type, sd, attrs);
  + ///
  + /// let out = ea.to_bytes();
  + ///
  + /// assert_eq!(out.len(), 86); // 86 is the length in this given case.
  + /// ```
  + ///
  pub fn to_bytes(&self) -> Vec<u8> {
  let mut vec = vec![];
  hs_cbor_util::encode_with_crc32(self, &mut vec);
  