README.md in blind_index-2.2.0 vs README.md in blind_index-2.3.0

- old
+ new

@@ -4,11 +4,11 @@
 
 Works with [Lockbox](https://github.com/ankane/lockbox) ([full example](https://ankane.org/securing-user-emails-lockbox)) and [attr_encrypted](https://github.com/attr-encrypted/attr_encrypted) ([full example](https://ankane.org/securing-user-emails-in-rails))
 
 Learn more about [securing sensitive data in Rails](https://ankane.org/sensitive-data-rails)
 
-[![Build Status](https://travis-ci.org/ankane/blind_index.svg?branch=master)](https://travis-ci.org/ankane/blind_index)
+[![Build Status](https://github.com/ankane/blind_index/workflows/build/badge.svg?branch=master)](https://github.com/ankane/blind_index/actions)
 
 ## How It Works
 
 We use [this approach](https://paragonie.com/blog/2017/05/building-searchable-encrypted-databases-with-php-and-sql) by Scott Arciszewski. To summarize, we compute a keyed hash of the sensitive data and store it in a column. To query, we apply the keyed hash function to the value we’re searching and then perform a database search. This results in performant queries for exact matches. Efficient `LIKE` queries are [not possible](#like-ilike-and-full-text-searching), but you can index expressions.
 
@@ -260,9 +260,10 @@
 For Mongoid, use:
 
 ```ruby
 class User
   field :email_bidx, type: String
+  index({email_bidx: 1})
 end
 ```
 
 ## Key Generation
 