README.md in ahoy_email-2.0.3 vs README.md in ahoy_email-2.1.0

@@ -283,9 +283,17 @@
 class CouponMailer < ApplicationMailer
   track_clicks campaign: "my-campaign", if: -> { params[:user].opted_in? }
 end
 ```
 
+You can also use a proc
+
+```ruby
+class CouponMailer < ApplicationMailer
+  track_clicks campaign: -> { "coupon-#{action_name}" }
+end
+```
+
 Skip specific links with:
 
 ```erb
 <%= link_to "Go", some_url, data: {skip_click: true} %>
 ```