Update readme

Author: weilu

README.md

@@ -3,11 +3,11 @@ bitcoin-tx-graph-visualizer
 
 Visualize bitcoin transactions using d3.js
 
-Below graph is generated with data found in `/example/transaction.json`.
+Below graph is a thumbnail of an SVG generated with data found in `/example/transaction.json`. Click to see the full version.
 
 ![Bitcoin transactions visualized](https://rawgithub.com/weilu/bitcoin-tx-graph-visualizer/master/example/transactions.svg)
 
-See `example` for sample usage. To run the example:
+See `example` for sample usage of this library. To run the example:
 
 ```bash
 git clone https://github.com/weilu/bitcoin-tx-graph-visualizer.git