Update README.md instructions.

Author: chrfrantz

README.md

@@ -1,12 +1,14 @@
 # DBSCAN
 Lightweight Java implementation of density-based clustering algorithm DBSCAN
 
-## Building
+## Download/Building
+
+You can download the latest jar file from the releases page.
 
 To build the library, you can either compile the sources manually or use maven (`mvn package`).
 
 ## Usage
 
-* Implement a distance metric for the data type to be clustered (using the interface `DistanceMetric`).
+* Implement a distance metric for the data type to be clustered (using the interface `org.christopherfrantz.dbscan.DistanceMetric`; for an example see the implementation `org.christopherfrantz.dbscan.metrics.DistanceMetricNumbers` or consult the tests).
 * Instantiate `DBSCANClusterer`.
-* Invoke `performClustering()`.
+* Invoke `performClustering()` to retrieve the clustered inputs. See tests for examples.