Rails Session setup example

[urkle]

By default using Sunspot::IndexQueue::SessionProxy.new configures things to run with default configuration and ignoring the config/sunspot.yml file. Which ignores key parameters like the port solr is running on)

Could the documentation in the README be updated to also include this recipe for Rails users

corrected
Sunspot.session = Sunspot::IndexQueue::SessionProxy.new Sunspot::IndexQueue.new(session: Sunspot::Rails.build_session)