title: Parcel plugin not working: returns string of path instead of string of contents
body: <p>I'm using Parceljs and I'm trying to load a GLSL shader as plaintext. I've installed both <code>parcel-plugin-glsl</code> and <code>parcel-plugin-shader-loader</code>, but both are not working.</p>
  
  <p>I import them in my .js file like this:
  <code>
  import vertexShader from "./vertex-shaders/basic.glsl";
  console.log(vertexShader);
  </code></p>
  
  <p>According to the documentation I should now receive the contents of the file as text, but when I log to the console I just get the path to the file (<code>/dist/823ef3822e0a8f71abe50187f7dc2e79.glsl</code>).</p>
  
  <p>I've installed the plugin using <code>npm install parcel-plugin-glsl --save-dev</code>, Parcel should handle the rest.</p>
  
  <p>What am I doing wrong?</p>