title: Grunt task to inject a files contents into a placeholder within another file
body: <p>I have a JavaScript file called toInject.js. I would like the contents of this file to be injected into another JavaScript file in the place of a comment placeholder <code>/* === toInject.js placeholder === */</code> through a grunt task. What grunt task is available to do this any what configuration is required?</p>
  
  <p><strong>Both files before grunt task has run:</strong></p>
  
  <p>toInject.js</p>
  
  <pre><code>alert('hello world');
  </code></pre>
  
  <p>myScript.js</p>
  
  <pre><code>function doSomething() {
      /* === toInject.js placeholder === */
  }
  </code></pre>
  
  <p><strong>Changes to myScript.js after grunt task has run:</strong></p>
  
  <p>myScript.js</p>
  
  <pre><code>function doSomething() {
      alert('hello world');
  }
  </code></pre>