Updated README

README.rst

@@ -2,11 +2,22 @@
  The Accounting API
 ====================
 
+--------------
+ Dependencies
+--------------
+
+-   ledger-cli version 3 (I have not tried with version 2.x)
+-   Flask (install by running ``pip install -r requirements.txt``).
+
+
 -------
  Usage
 -------
 
 .. code-block:: bash
 
+    # Run the web service
+    LEDGER_FILE=../path/to/your.ledger ./bin/serve
+
     # Run a simple example
     python3 accounting/__init__.py