title: How do I extend a typings declaration?
body: <p>I'm using an npm module that has declarations in the DefinitelyTyped/DefinitelyTyped github repo, but typings for the module are incomplete.</p>
  
  <p>I have made a pull request to get the missing declarations in, however until its accepted I need to have a way to temporarily extend the incomplete declaration.</p>
  
  <p>Ideally I would like to be able to have a <code>temporaryTypings.d.ts</code> file in my project root where I can add declarations for every situation like this that I run into.</p>