Fix varying margins under headings

It seems that browsers add some special default styling to header tags :(

I found that for smaller heading tags, like h5 could give more padding then h1 tags...

To fix this, everything should now just recieve the theme standard of 24px bottom margin.

Author: Blendify

sphinx_rtd_theme/static/css/theme.css

@@ -14,6 +14,10 @@
 // --------------------------------------------------------------------------------------------------------------------
 
 .rst-content
+  // Some browsers like to give arbituary margins :( make them all consistent.
+  h1, h2, h3, h4, h5, h6
+    margin-bottom: $base-line-height
+
   // Sphinx by default applies HxW style attributes to images. This fixes that oversite.
   img
     max-width: 100%