title: Custom Intellisense Extension
body: <p>I am wanting to write an addition to intellisense in Visual Studio. </p>
  
  <p>Is it possible to extend at all, from my research I haven't found any samples or documentation on intellisense extensions.</p>
  
  <p>How can I get intellisense to show a simple HelloWorld message like the following (where hello world is added at run time to the intellisense for String):</p>
  
  <p><img src="https://i.stack.imgur.com/1Wfpt.png" alt="enter image description here"></p>