title: Webpack hot reloading stops on wrong typings error
body: <p>I've got a project in React + Typescript + Webpack stack and I'm using react-data-grid package with @types/react-data-grid package. The problem is that the typings provided in @types/react-data-grid are not complete. Which results in typescript error when trying to use one of the properties. However I know this property exists and it's just the matter of incomplete typings. So I've got two issues I would like to resolve:</p>
  
  <ol>
  <li><p>Add appropriate typings that would work together with @types/react-data-grid. Is there and option to that? That somehow typescript compiler would merge my new typings with @types/react-data-grid and stop showing the error?</p></li>
  <li><p>Enable Hot Reloading in Webpack. Even thought the typings error is shown ,still the bundle is created and after refreshing page while using webpack-dev-server. So I can actually develope but it would be nicer to have hot reloading. Is there an option to tell webpack-dev-server to ignore typescript errors? I just want to do it in the meantime and later fix the issue with Ad. 1.</p></li>
  </ol>
  
  <p>I am using:</p>
  
  <p>"ts-loader" : "^4.1.0",
  "typescript" : "^2.7.2",
  "webpack": "^4.2.0",
  "webpack-cli": "^2.0.13",
  "webpack-dev-server": "^3.1.1"</p>