title: Angular CLI ng serve with --base-href - I do not understand its behavior
body: <p>I am new in Angular CLI.
  I am writing an new app, and in the <code>index.html</code> I insert <code>base href</code>, 
  for example - <code>&lt;base href="/a/"&gt;</code>.</p>
  
  <p>When I use<code>ng serve</code> and go to <code>localhost:4200/a</code> (or even <code>localhost:4200</code>) I see a white screen, but when I use <code>ng serve --base-href /a/</code> I see my app in <code>localhost:4200</code>, in <code>localhost:4200/a</code>, and actually in every url that starts with <code>localhost:4200</code> for example <code>localhost:4200/aaaaaaa</code>.</p>
  
  <p>I do not understand this behavior.</p>
  
  <p>From the documentation I understood that this flag just change the <code>base href</code> in <code>index html</code>, but I already have this base href in my <code>index.html</code> so why my app doesn't work just with <code>ng serve</code> in <code>localhost:4200/a</code>?</p>
  
  <p>And why when I use <code>ng serve --base-href /a/</code> it is not working ONLY at <code>localhost:4200/a</code>? what do I miss? 
  I am really confused.</p>
  
  <p>Thanks!</p>