traceapp: use a standard 2-space indention in HTML template files.

Prior to this change there was a mixed use of:

Two-space indention (used all the time after this change is merged):

<html>
  <div>
    <strong>foo!</strong>
  </div>
</html>

Two-space indention with a leading one space indention (hard to work with in most editors):

<html>
 <div>
   <strong>foo!</strong>
 </div>
</html>

Tabs for indention.

I chose to go with 2-space indention due to that being used most prominently in the code base already. The usage of tabs (code I wrote) was accidental.

After this change we use just two-space indention for all HTML/CSS/JS code.

sourcegraph / appdash

traceapp: use a standard 2-space indention in HTML template files. #49