[Rails] Easily enable Yandex.Metrika support in your Rails application. <br/><br/> By default this gem will output Yandex.Metrika code for every page automagically, if it's configured correctly. This is done by adding: <br/> Yandex::Metrika.counter_id = '123456' <br/> to your `config/environment.rb`, inserting your own COUNTER_ID. This can be discovered by looking at the value of "new Ya.Metrika(123456)" in the Javascript code.