The files in `_includes` are generated from other sources. This change (and the change to the `sinatra-streaming` docs) will be overwritten when the docs are regenerated. It should be made in the [sinatra-contrib repo](https://github.com/sinatra/sinatra-contrib/blob/dc38ff1a4a46a27dbb9241d40b15472d8097761d/lib/sinatra/config_file.rb#L73).

(It’s not obvious that it’s generated – I did [the same thing a while ago](https://github.com/sinatra/sinatra.github.com/pull/50)).