title: How to add a logo to my readthedocs - logo rendering at 0px wide
body: <p>This happens locally via sphinx running readthedocs theme, it also happens in readthedocs.io.</p>
  
  <p>I have added an svg logo (actually it's just the downloaded rtd logo.svg copied from their site for testing).</p>
  
  <p>I've added the settings to <strong>conf.py</strong> and html builds fine.</p>
  
  <pre><code>html_theme = 'sphinx_rtd_theme'
  html_static_path = ['_static']
  html_logo = 'logo.svg'
  html_theme_options = {
      'logo_only': True,
      'display_version': False,
  }
  </code></pre>
  
  <p>If I inspect the logo class in Firefox it is set to "auto", if I add a width in px, the logo appears.</p>
  
  <p>I feel as if I am missing something about the configuration of the readthedocs theme in the conf.py file?</p>
  
  <p>Surely I should not have to hack at the CSS manually: I see no indication of altered CSS in the Readthedocs.io site when looking at their source.</p>
  
  <p>I'm looking for an elegant solution - I do not want updates to readthedocs theme to break my site because I have been overriding the theme's CSS.</p>