Update README.md.

This commit adds a description, status, and major features to the README.

README.md

@@ -6,9 +6,16 @@ btcrpcclient
 [![GoDoc](https://godoc.org/github.com/conformal/btcrpcclient?status.png)]
 (http://godoc.org/github.com/conformal/btcrpcclient)
 
-This package is currently under development.
+btcrpcclient implements a Websocket-enabled Bitcoin JSON-RPC client package
+written in [Go](http://golang.org/).  It provides a robust and easy to use
+client for interfacing with a Bitcoin RPC server that uses a btcd/bitcoin core
+compatible Bitcoin JSON-RPC API.
 
-You really probably don't want to use this yet!
+## Status
+
+This package is currently under active development.  It is already stable and
+the infrastructure is complete.  However, there are still several RPCs left to
+implement and the API is not stable yet.
 
 ## Documentation
 
@@ -21,6 +28,19 @@ You really probably don't want to use this yet!
   Connects to a bitcoin core RPC server using HTTP POST mode with TLS disabled
   and gets the current block count
 
+## Major Features
+
+* Supports Websockets (btcd/btcwallet) and HTTP POST mode (bitcoin core)
+* Provides callback and registration functions for btcd/btcwallet notifications
+* Supports btcd extensions
+* Translates  to and from higher-level and easier to use Go types
+* Offers a synchronous (blocking) and asynchrous API
+* When running in Websockets mode (the default):
+  * Automatic reconnect handling (can be disabled)
+  * Outstanding commands are automatically reissued
+  * Registered notifications are automatically reregistered
+  * Back-off support on reconnect attempts
+
 ## Installation
 
 ```bash