title: Custom Content-Type for File in Rails 'public' Folder
body: <p>For assets stored in the 'public' folder of a ruby-on-rails application is it possible to change the 'Content-Type' when running 'script/server'? For example, I am attempting to create an HTML5 application supporting offline mode, and have an 'offline.manifest'. When I run:</p>
  
  <pre><code>curl -I localhost:3000/offline.mainfest
  </code></pre>
  
  <p>The following header information is returned:</p>
  
  <pre><code>HTTP/1.1 200 OK
  ...
  Content-Type: text/plain
  ...
  </code></pre>
  
  <p>However, HTML5 specifications require:</p>
  
  <pre><code>HTTP/1.1 200 OK
  ...
  Content-Type: text/cache-manifest
  ...
  </code></pre>