Isolate indexes

.gitignore

@@ -1,3 +1,2 @@
-.env
-data/
 node_modules/
+package-lock.json

README.md

@@ -4,25 +4,25 @@
 
 An external [bitcoind](https://github.com/bitcoin/bitcoin) index management service.
 
+
 ## Indexes
-By default,  this module maintains script, spents, transaction block, txout and block indexes.
+By default,  this module includes a script, spents, transaction block, txout, tx, median time past and fee indexes.
 The module uses `getblockheader`, `getblockhash`, `getblock` and `getbestblockhash` RPC methods for blockchain synchronization;  and `getrawmempool` for mempool synchronization.
 
 `-txindex` is not required for this module; but is still useful for individual transaction lookup (aka `txHex`).
 See https://github.com/bitcoinjs/indexd/issues/6 if you think an independent transaction index should be added.
 
+
 ## Usage
-Assumes [`yajrpc`](https://github.com/dcousens/yajrpc) is used for the bitcoind RPC; and [`leveldown`](https://github.com/level/leveldown) for the database.
-See the [example](#example) for usage.
+Assumes [`yajrpc`](https://github.com/dcousens/yajrpc) is used for the provided bitcoind RPC object; and [`leveldown`](https://github.com/level/leveldown) for the database object.
+See the [example server](https://github.com/bitcoinjs/private-bitcoin) for an example of an express HTTP API using `indexd`.
+
 
+### Conventions
+When conveying block height, `-1` represents unconfirmed (in the mempool).
+`null` represents unknown or missing.
 
-## Example
-The [`example/`](https://github.com/bitcoinjs/indexd/tree/master/example) is a functioning [express](https://www.npmjs.com/package/express) REST HTTP API server.
+For example, the height of the transaction `ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff` in the Bitcoin blockchain is `null` (it doesn't exist!).
 
-* Requires a running `bitcoind` node
-	* with `-txindex`, and
-	* ZMQ (`-zmqpubhashtx=tcp://127.0.0.1:30001 -zmqpubhashblock=tcp://127.0.0.1:30001`)
-* Assumes `--testnet` ports/configuration, see `example/.env` for configuration.
-* Change `-rpcworkqueue` from `16` to `32` for increased throughput [in some scenarios]
 
-## License [ISC](LICENSE)
+## LICENSE [ISC](LICENSE)