title: What does this [Option(...)] C# attribute mean?
body: <p>What does this C# attribute mean? I am mostly working with C++,
  and I do know about the concept of attributes in C#, but not sure about this one:
  It is in a class. So basically we have a property, and an attribute for it.</p>
  
  <pre><code>[Option("h", "help", HelpText = "Shows this help message")]
  public bool Help { get; set; }
  </code></pre>
  
  <p>Thanks</p>