Update the documentation for Ruby version support

README.rdoc

@@ -16,6 +16,7 @@ Read the blog post introducing PgSearch at http://pivotallabs.com/pg-search/
 
 == REQUIREMENTS
 
+* Ruby 1.9.2 or later
 * Active Record 3.1 or later
 * PostgreSQL
 * {PostgreSQL contrib packages for certain features}[https://github.com/Casecommons/pg_search/wiki/Installing-Postgres-Contrib-Modules]
@@ -24,7 +25,7 @@ Read the blog post introducing PgSearch at http://pivotallabs.com/pg-search/
 
  gem install pg_search
 
-=== Rails 3.1 or later
+=== Rails 3.1 or later, Ruby 1.9.2 or later
 
 In Gemfile
 
@@ -52,6 +53,14 @@ In addition to installing and requiring the gem, you may want to include the PgS
 
  load "pg_search/tasks.rb"
 
+=== Ruby 1.8.7 or earlier
+
+The newest versions of PgSearch no longer support Ruby 1.8.7. However, the 0.6 series still works. It's not actively maintained, but submissions are welcome for backports and bugfixes.
+
+ gem 'pg_search', "~> 0.6.4"
+
+The 0.6 branch lives at https://github.com/Casecommons/pg_search/tree/0.6-stable
+
 == USAGE
 
 To add PgSearch to an Active Record model, simply include the PgSearch module.