Add 'error handling' section to readme

README.rdoc

@@ -446,6 +446,13 @@ Geocoder comes with a test suite (just run <tt>rake test</tt>) that mocks Active
 http://github.com/alexreisner/geocoder_test
 
 
+== Error Handling
+
+By default Geocoder will rescue any exceptions raised by calls to the geocoding service and return an empty array (using warn() to inform you of the error). You can override this and implement custom error handling for certain exceptions by using the <tt>:always_raise</tt> option:
+
+  Geocoder::Configuration.always_raise = [SocketError, TimeoutError]
+
+
 == Known Issue
 
 You cannot use the +near+ scope with another scope that provides an +includes+ option because the +SELECT+ clause generated by +near+ will overwrite it (or vice versa). Instead, try using +joins+ and pass a <tt>:select</tt> option to the +near+ scope to get the columns you want. For example: