add some docs for merb use to the README

README

@@ -16,6 +16,7 @@ If you use this software, please {make a donation}[http://blog.evanweaver.com/do
 * MySQL 5.0, or PostgreSQL 8.2
 * Sphinx 0.9.8-rc2
 * Rails 2.0.2
+* instead of Rails, Merb 0.9.3 is now supported
 
 More recent versions than listed are usually ok.
 
@@ -65,6 +66,34 @@ Now, in your models, use the <tt>is_indexed</tt> method to configure a model as
 
 For more index options, see ActiveRecord::Base .is_indexed.
 
+== Merb Installation
+
+Install Sphinx as above.
+
+Download the latest version of this code from git:
+  git clone git://github.com/jamie/ultrasphinx.git
+
+Build the gem:
+  rake package
+
+Install the gem into your merb application locally:
+  gem install pkg/ultrasphinx-1.11.gem -i ~/projects/sample/gems
+
+In config/init.rb, add these lines:
+  require 'erb' # for Ultrasphinx
+  require 'active_support' # for Ultrasphinx, mattr_accessor
+  dependency 'ultrasphinx'
+
+Finally, copy the example configuration file over, and configure as usual.
+
+Merb support includes ORM support for both DataMapper >0.9.2 and
+ActiveRecord >2.1.0, detected automatically.
+
+All other usage and configuration is the same as for Rails.  As sphinx
+interacts directly with the database, the actual technology used in an app
+is less important than ensuring that the database and configuration file are
+correct.
+
 == Building the index
 
 Now run: