title: Automatically reloading shiny app when add changes
body: <p>I would like to have an option (when working locally) which allows me to see changes in my shiny app automatically after I put some changes in <code>server.R</code> or <code>ui.R</code> file. It is really annoying to manually rerun <code>runApp</code> function every time I add a new thing. </p>
  
  <p>The optimal solution which I really like is <code>xaringan::inifinite_moon_reader</code> function which is extremely helpful.</p>
  
  <p>Is there any solution which do this stuff?</p>
  
  <p>You can find analogical solution <a href="https://res.cloudinary.com/practicaldev/image/fetch/s--62zUz5UZ--/c_limit%2Cf_auto%2Cfl_progressive%2Cq_66%2Cw_880/http://willamesoares.com/images/posts/d3/d3example.gif" rel="noreferrer">here</a>. On the right, the code was modified and saved, on the left, the content of page was updated.</p>