title: Importing proto file from different package
body: <p>I have two services: Story and Tag. The files are structured in this way:</p>
  
  <pre><code>Story
  |-- StoryService
  |   `-- proto
  |       `-- storyservice.proto
  `-- TagService
      `-- proto
          `-- tagservice.proto
  </code></pre>
  
  <p>Each one of <code>.proto</code> files needs to use messages from the other one. How can I import them into each other?
  I tried <code>import "StoryService/proto/storyservice.proto"</code> but it didn't work.</p>