appdx: fix commentaries in code

appdx-bitcore.asciidoc

@@ -55,11 +55,11 @@ Creating and signing a transaction from an UTXO:
 
 ----
 > utxo = {
-  txId: transaction id containing an unspent output,
-  outputIndex: output index e.g. 0,
+  txId: txId, // transaction id containing an unspent output
+  outputIndex: outputIndex, // output index (e.g. 0)
   address: addressOfUtxo,
   script: bitcore.Script.buildPublicKeyHashOut(addressOfUtxo).toString(),
-  satoshis: amount sent to the address
+  satoshis: satoshis // amount sent to the address
 }
 > fee = 3000 //set appropriately for conditions on the network
 > tx = new bitcore.Transaction()